Shows what you know about the lore.
For one, as anyone should, there should be lore consistency with D&D. And there hasn't been since after 3e.
You think that setting-lore-inconsistency is something that Wizards of the Coast invented for D&D? That is just laughably wrong. How many retcons and world-changing events happened to official D&D settings while TSR was in charge? There was the Time of Troubles for the Forgotten Realms, the Prism Pentad for Dark Sun, and the various different eras and versions of the Dragonlance setting all before TSR was bought by WotC. Lore retcons and inconsistencies within D&D settings have been around
waaaaay earlier than D&D 3e.
If anything, Wizards of the Coast inherited a mess of lore-inconsistencies and revisions that they had to sort through and choose to do their own take/versions on.
WotC doesn't need to shove core aspects of the generic game into every single world. I thought each setting was supposed to be different?
They are. They still are. Have you bought any recently published setting books? The settings are absolutely different. Strixhaven is completely different from Theros, which is completely different from Eberron, which is completely different from Ravenloft, which is completely different from Exandria, which is completely different from Ravnica. Sharing a few common aspects between most/a few settings is absolutely nothing new to D&D, and is something that's been a part of the hobby since it began. Ever since the game was released, there have always been base assumptions about the races/monsters that will be included there. Most settings in TSR-era D&D included Dwarves, Elves, Halflings, and Humans, and often also included Goblinoids, Orcs, Kobolds, Gnolls, and all of the same classes. Mystara, Greyhawk, the Forgotten Realms, Dark Sun, and Dragonlance all had Dwarves, Elves, Halflings (well, Kender for Dragonlance, but they are basically the same thing), and Humans. Out of those five settings, only Dragonlance and Dark Sun don't Goblinoids, Orcs, and Gnolls.
Each setting can absolutely be very different from each other while also sharing common elements. Dark Sun is absolutely different from Eberron and Mystara, even if they all share similar races.
How does force-feeding Feywild material onto a race that has had dozens of novels dedicated to portraying their origin and lifestyle a good thing people are supposed to just accept? I find it illogical to mess with what was never broken or wrong. It's like someone taking your pepperoni pizza the way you like it and just pouring tobasco sauce all over it for no reason other than "It's what we believe will sell better to the new customers and not old customers like you."
Again, blame TSR for this. A shared multiverse has been a thing in D&D since AD&D, with the introduction of the Planescape and Spelljammer settings. Connecting the Feywild to the a lot of D&D settings is no more outrageous than giving every D&D world a Crystal Sphere and the Great Wheel Cosmology.
They were magical in origin only, other than that they're not really fey and never had a connection to them. They're simply kleptos which explains why they had random items on them. Nothing magical about it. Nothing Fey about it. But now they're literally "pulling rabbits out of hats" is ridiculous and a travesty to the fans of the setting. Even the Taunt is supernatural!? Really? It's not because they've spent centuries perfecting the art instead?
"There was nothing magical about them" and "they had magical origins" are contradictory statements. Also, getting rid of the main thing that made many DMs and players hate the race (genetically-enforced kleptomania) is overall a beneficial thing to the setting and game as a whole.
What I can't fathom is the logic that WotC needs to rearrange the lore on things that don't need changes to begin with. I say 99% of the edition war issues is because of them creating divisiveness amongst the base by messing with things in D&D that shouldn't be messed with. Improved upon, yes. Retcon? No.
Here's the thing, you're saying that retconning something is inherently bad. I fundamentally disagree with this. If Gully Dwarves get retconned out of existence, I think that would absolutely be a good thing. They're chock full of ableist and bigoted stereotypes of mentally disabled peoples, and definitely should not be published in this day and age. Getting rid of them would be a retcon, yes, but retcons are not fundamentally bad things. Retcons are tools. They can be misused, yes, just like every other tool in existence, but their usage does not inherently imply that the people doing the retcon are messing something up.
Something can be improved upon by a retcon. Obviously not all retcons are good, but they're not all bad, either. Especially if there is something wrong with the source material (which Dragonlance is full of).
I'm no Dark Sun fan, but ask a Dark Sun fan how they would feel if their setting got Feywild material suddenly shoved in Athas by WotC if they ever brought it back.
4e already had Dark Sun with the Feywild. And from what I've seen in this thread, it's actually pretty popular, being an interesting take on the plane of existence in the setting.