I'm A Banana
Potassium-Rich
Tastes vary, I suppose. I know that one of my best experiences in 3rd Edition was playing Living Greyhawk in the Geoff region, which had a lot of interaction with fairies at their most capricious - even amongst the ones theoretically on your side, you had to step very carefully and beware the slightest mispoken word.
That sounds awesome.

That was an element of fairykind that, I felt, was not the 'default' in the core rules. And it made for an excellent experience... as composed to past occasions where pixies would crop up basically as... a joke.
That sucks more.
Sounds like there were some fairies that lacked conflict, which I do agree is very important. Shouldn't be too hard to inject back in, though. Even the Campestri have a potentially interesting conflict in them (and can be ignored in favor of sidhe and unseelie if giddy little mushrooms aren't your playstyle!).
Now, of course, as that very experience indicates, one could run 'darker' faeries without 4E being in the picture at all. But again, I don't think it was the default, and I think that was the focus of the statement - not to dismiss non-combat interactions with faeries, but to focus on making the fair folk into truly terrible beings (whether one fights them or not), rather than simply leave them as 'cute'.
I'm on board with this for specific instances, but not for the whole category.
For instance, Dryads. I think it was a mistake for 4e to turn them into tree monsters. I think this because I don't think they need to be tree monsters to be a credible challenge for the party. A fair maiden tethered to an ancient oak with supernatural powers over the entire forest is a good challenge for a party without turning it into a tree monster. It's not necessarily a good combat challenge -- she's an unarmed maiden, though she could certainly be surprisingly adept at killin' PCs -- but it's a great Interaction challenge (convince her not to bar our way through her woods!) or a great Exploration challenge (Find the oak to which she is tied!), or a solid Investigation challenge (What pernicious creature keeps killing loggers in the woods?).
At the same time, I definitely think there's room for critters who present that aura of alien malice. I just wouldn't turn EVERYTHING into that. Again, it goes back to the "It shouldn't just be one thing" argument I'm hitting a lot here.

I'll admit - that may be an overly generous reading, especially given the specific comparison about slaying monsters vs interacting with the little people. But I think the other elements of that statement, plus his own attitude as shown elsewhere, give a slightly different reading than the claim that he just dislikes all non-combat interaction.
Anyway, just my opinion, and I'll admit I have no special insight into his true meaning.
I'm willing to bet James Wyatt has had some great sessions where narry an attack roll was rolled.
But I also found that his words and designs near the opening of 4e specifically aggravated my "This is not my D&D! What!?" reaction. Things like the new dryad. Which I wouldn't have given a fig about if it was just some new "Treeling" kind of monster, honestly.