Brian Aldiss famously dubbed John Wyndham “the master of the cosy catastrophe”, and so damned him with an adjective. 
Now, whenever anyone writes about Wyndham, they dig that one up. “The essence of the cosy catastrophe,” Aldiss says in Trillion Year Spree, “is that the hero should have a pretty good time (a girl, free suites at the Savoy, automobiles for the taking) while everyone else is dying off.” I can’t help feeling Aldiss’s scorn for Wyndham extended just as much to his readers — his many readers, I should say. This is what he says about The Day of the Triffids and Wyndham’s next novel, The Kraken Wakes:
“Both novels were totally devoid of ideas but read smoothly, and thus reached a maximum audience, who enjoyed cosy disasters. Either it was something to do with the collapse of the British Empire, or the back-to-nature movement, or a general feeling that industrialisation had gone too far, or all three.”
(There’s always an explanation for other people’s reading tastes.)
In Science Fiction: The Illustrated Encyclopedia, John Clute takes the same view:
“And in 1951 came The Day of the Triffids, a tale that captured the insecurities of the middle-class English reader in the austerity years perfectly, and envisioned to a nicety the kinds of self-protective communities that would comfort that readership… The comforting implausibility of this outcome, along with the calm, analgesic style of the Wyndham persona, contribute to what Brian Aldiss called the Cosy Catastrophe.”
“Middle-class”, here, is used with as much a sense of derision, or at least belittlement, as “cosy” and “comforting”, which is, let’s face it, a very middle-class thing to do (trying to distance oneself from middle-class guilt through being tough on the middle classes). 
Perhaps it was Wyndham’s success — and the fact that his readership inevitably would have been larger than a dedicated SF readership (far less of a sin nowadays) — or perhaps it was that Wyndham’s revolt against the way things were didn’t go far enough for Aldiss, who was of the next literary generation, SF’s New Wave, that wanted the far more extreme revolutions of the 1960s. (For me, the best New Wave response to Wyndham’s novels is Ballard’s: he rewrote them, as The Wind from Nowhere, The Drowned World, The Burning World, and the surreal The Crystal World, thus developing them, rather than merely critiquing them. Aldiss himself wrote a catastrophe or two. Greybeard was one I remember reading, but Hothouse (not a catastrophe), a far-future jungle Earth where pretty much every other plant is a triffid of some sort, is the novel of his I most enjoyed.)
I’ve never subscribed to the idea that reading should be a sort of mental & moral cold bath. I like reading for pleasure. I like things that “read smoothly” (which, to me, is evidence of craft), and don’t see why I shouldn’t. I wouldn’t go so far as to say I like my reading “cosy” and “comforting”, but I certainly wouldn’t go to a book for the purposes of self-torture.
The main “cosy” aspect of the “cosy catastrophe” is, I suppose, the fact that the catastrophe doesn’t completely destroy the world, but offers a chance to start again. As someone says in Triffids:
“The Earth is intact, unscarred, still fruitful. It can provide us with food and raw materials. We have repositories of knowledge… And we have the means, the health, and the strength to begin again.”
But this doesn’t mean there’s nothing but cosiness, comfort and having it your own way. The Day of the Triffids has an inviting air of adventure, of working out what you’d do in the hero’s place, of treating the world you know as a sort of imaginative playground for looting, shooting and uprooting; but it also has moments of real poignance, as when a young woman, blinded and now dying from disease, says:
“So futile — and it might all have been so different.”
Which perfectly captures, I think, the sense of a young life ending too early. And the beginning of chapter 13 strikes such a heartfelt note of loneliness, it’s impossible to believe Wyndham’s hero was simply having a good time in this de-populated England:
“Until then I had always thought of loneliness as something negative — an absence of company, and, of course, something temporary… That day I had learned that it was much more. It was something which could press and oppress, could distort the ordinary, and play tricks with the mind. Something which looked inimically all around, stretching the nerves and straining them with alarms, never letting one forget that there was no one to help, no one to care.”
Day of the Triffids is, I think, a truly good read. The opening two chapters have an almost classical perfection as openings go: the first, so tightly focused on the narrator’s immediate predicament (in a hospital bed waiting for someone to remove his eye-bandages, he starts to be aware from the sounds alone that something is deeply wrong), while the second chapter is almost pure exposition, as the appearance of the triffids is described alongside a potted biography of the narrator. After that, we’re set up and onto the adventure.
Triffids wasn’t Wyndham’s first book — he’d been published before the Second World War in the US pulps, under different names, and had had two detective novels published in the UK — but it was the first of his new approach, something he called “logical fantasy”, which downplayed the pulpier SF elements (all the wilder speculations about the triffids’ possible intelligence, for instance, are placed in the mouths of characters other than the narrator, allowing him to sound skeptical, and so reassure the reader they aren’t in the hands of a whacko).
The Kraken Wakes is a more disappointing book. Whereas the emphasis in Triffids is on the immediate survival of the characters and, later, the far-range survival of the human race, Kraken is mostly about the slow unfolding of the initial catastrophe (a lot of which is by secondhand report, distancing the reader from the action). As a result, it’s far more about something that’s only a minor note in Triffids: how reluctant people are to believe in anything outside their daily experience. In Triffids this comes out in the way most people belittle Bill Masen’s warnings about how dangerous the triffids are going to be in this newly-depopulated England. Kraken, on the other hand, is so much more about the media, and the way it, and its readership, mocks any suggestion they may be experiencing the opening stages of an alien invasion until it’s too late (and even then they still want to blame it on the Russians). So Kraken reads more like a satire on modern civilisation than Triffids’ straightforward adventure, and I don’t think Wyndham has the bite for satire. Also, in contrast to Triffids, Kraken is set in a still-socialised world, and feels bogged down in the highly straightjacketed manners of its time. So, in Kraken we get the rather dated spectacle of the protagonist’s wife having a sudden rant (about the need for the government to arm the people, of all things), then apologising for the display and taking herself off for a lie-down. Then a doctor is called, as though any sign of emotion were cause for medication.
What’s most surprising about Kraken is that, though it was published in 1953, it reads so much like a reaction to the 1956 Suez crisis, and the final end of the British Empire:
“We, a maritime people who rose to power upon shipping which plied to the furthest corners of the earth, have lost the freedom of the seas. We have been kicked out of an element that we had made our own.”
Triffids is the better book: yes, “smoothly written”, but not merely cosy. And the 1981 BBC adaptation had one of the spookiest TV theme tunes of all time (if you can call that eerie choral drone a tune).
