I'll give you that! While I think that the eladrin race was a genius addition to D&D during 4E, the way the race was retconned into the Realms was . . . awkward. I liked the eladrin citadel in the Moonshaes rising out of the lake into the material world, but the switch back-and-forth with Sun and Moon elves was jarring and not handled well. It was also confusing that some elven races were *always* eladrin, and others just entered the world for the first time. If the Realms had been completely reimagined (a la Battlestar Galactica), I would have probably been fine with the retcon of Sun elves being eladrin (or was it Moon, or both?).
I didn't mind their inclusion in Eberron, because they were an addition, not a retcon (if I remember correctly). The trapped feyspires throughout the land were an interesting addition to the world, IMO.
I believe they retconned the origin of elves in Eberron, but that was mostly additive, which was much easier. Ditto Dark Sun.
It might have been a response to the awkward retconning of the Realms. Or not. (I'm rather happy we didn't get Dragonlance after all, as they likely would have suggested the Silvanesti were from the feywild too.)
We're not talking Warcraft or LotR, we're talking D&D. And elven subraces in D&D have long been an "issue", albeit one that some folks felt strongly about and others didn't even notice. Multiple subraces that aren't all that different (high vs grey, wild vs wood) in the core and an overabundance of offshoot subraces. This "problem" (not really a problem, just a thing) did not *need* fixing, but I welcomed the cleaner break down of eladrin-drow-elf in 4E, and I was not alone at all on that one.
The subrace problem was mostly a greyhawk one as the difference between high vs. grey vs. wood was subtle. And Dragonlance did the same by renaming but making them all unpronounceable (silvanesti, qualinesti, and kagonesti). I thought forgotten realms with its sun/gold elves, moon/silver elves, and copper elves was a little more memorable.
The reasoning made sense. High, grey, wood equals Eldrond, Galadriel, and Legolas. But it is one too many. I'm happy with the 5e overlapping of high and grey.
On the other hand, many not-all-that-different subraces of elves is a part of D&D history just like the wild Great Wheel cosmology and calling a class "fighter" when a much better name would be "warrior". Change it at your own risk, which, of course, was part of why 4E was so divisive among fans.
It's certainly emblematic of 4e's attitude to the game's history. But I think you can like/hate eladrin on their own merits. Or, such as me, like the concept but hate the reasoning.
No, no it wasn't. Not in the slightest. Absolutely no one's intelligence was insulted by the elven subrace change in 4E. Love or hate the race and the various reasons behind the change, but the change itself was in no way insulting. Jeesh.
I felt a little insulted. There were too many subraces but the solution is to reduce and streamline, not dump the whole idea.
"People are confused by our 52 flavours of iced cream. Let's just serve vanilla. And chocolate frozen yoghourt for cocoa fans.
It was a lot like the metallic dragons.
"People find brass, bronze, and copper confusing and interchangeable."
"Well, we could emphasise their differences and think of mnemonic ways of making them distinct."
"Naw, let's just replace them with mithril and adamantine."
That's insulting and annoying regardless of the edition the change is being done for.
5e gets it just right. There are three major tropes of elf in D&D so there are three types of elf: high, wood, and drow. Those don't need to be different races, but neither do we need grey and wild.
But, really, you need not even go that far. Essentials showed eladrin were kinda superflous when it gave elves the stats of +2 Dex, +2 Wis/Int, as they could easily be a wizard or a ranger with no confusion and the racial power worked for both. Eladrin pretty much existed because the designers couldn't give elves a choice in ability scores but wanted the race to be equally perfect for wizard and ranger.