And yet, this was the edition that made storm giants evil, gold dragons unaligned, bumped bronze and brass dragons for iron and adamantine, made succubi devils, blue dragons coastal, and ended angels being the epitome of goodness. None of that has anything to do with Planescape, and everything to do with outright contradiction of the monsters that have been that way since the 1e Monster Manual.
You don't think "chucking 30 years of lore" is slightly hyperbolic? The Nine Hells didn't change from their PS status-quo. Goblins worshipped Maglubiyet, bugbears Hruggek, drow Lolth. Bahamut was the god of metallic dragons, Tiamat of chromatics. Etc, etc.
The fact that you and others can itemise half-a-dozen things (and they're the same recurring ones - eladrin, storm giants, angels, archons, dragons, succubi) seems to suggest that rather than chucking everything, there was a rather finite list of changes.
Also, they didn't "bump" bronze and brass dragons. They just introduced some new metallic dragons - which (I've been told) is addition, not alteration.
4th Edition Lore
[Blue dragons] can be found anywhere but prefer to lair in coastal caves, attacking and plundering ships that sail too close.
Blue Dragon Lore
...
DC 15: Although highly adaptable, blue dragons often lair in coastal caves with entrances that aren't easily accessible by land.
1st Edition Lore
Blue dragons typically prefer deserts and arid lands; like others of their kind their lair is always some vast cave or underground cavern.
I have no problem with these two pieces of lore existing side-by-side. Neither the 1st Edition nor 4th Edition lore prohibits blue dragons from existing in other environments. In fact, the 1st Edition DMG random monster encounter dragon subtable has all dragon types existing in each environment. As far as lore changes go, this one is not egregious.
They're also not inconsistent. There are many arid coasts in the real world, so there's no reason to suppose that the world of D&D lacks them.
This would seem to be another example of addition, not change!
Wait, lore changes are not egregious now?
It's not a change, it's an addition. Because both bits of lore are obviously consistent. They live in coastal deserts.
Does writing pages of justification for a bad mistake make it not a bad mistake? Or does it just try and spread the blame around so that you are not left as the one responsible for that mistake?
Well, not everyone thinks it was a bad mistake, do they.
If someone writes something that (i) you don't like, and (ii) is inspired by or derived form something you like, it's of course your prerogative not to like it. But it doesn't follow that they misunderstood, or hated, or set out to destroy or "chuck", the stuff that you liked. Worlds & Monsters explains their reasoning - combining aesthetic considerations with considerations of gameplay - in detail. You might not like the reasons. You might not like what the reason led to. But the reasons were there.
Some people like Monet but don't like Cezanne; that doesn't mean that Cezanne's work is not a legitimate response to, and development from, impressionism. And the point becomes even more obvious if one then continues the development/response through to Picasso and cubism.
Well, if Andy Collins making fun of Planescape fans is "deep regard" then I guess we can call it deep regard
What are you talking about? Not Worlds & Monsters, at any rate, which is what I was referring to.
4e preserves huge chunks of PS - all the Nine Hells, stuff, for instance. It still has the Blood War. And Sigil is prominent in two supplements (MotP and DMG 2). You can certainly get more PS than (say) GH from the 4e books, although I would say that GH has been the more significant source of lore over the course of D&D's history.