That may have been true on some boards. It wasn't really true that it was a "construct" here, though. A lot of vocal critics of 4E openly stated that they hadn't played it, which was refreshingly transparent, but obviously meant that a lot of the arguments involved were very hard to actually have, because many critics couldn't substantiate points or expand on them. That's actually what really showed me that a lot of opinions are really low-value/low-effort (and caused me to question some of my own less-supportable opinions as a result).
A particularly common and dubious argument I saw was that 4E was "basically the same thing as World of Warcraft"*. If that sounds vague, it's because this was indeed a nebulous and ill-defined talking point, and the vast majority of people who used it had never played World of Warcraft (again, this was openly admitted). In some cases they'd played neither WoW nor 4E, by their own admission, but were repeating this talking point! I also heard it from a couple of people IRL (one of whom later joined my 4E group!), who had equally never played 4E or WoW.
It was kind of fascinating, from a cultural viewpoint. It's not a reaction I'd seen much re: RPGs before. I'd seen plenty of edition wars, before, but they tended to be fought over very specific rules, or setting changes, which were well-understood (the one major exception being 1E-2E D&D which had elements of that, but seemed to mostly be concerned with nebulous perceived changes of tone, a lot of which couldn't really be pinned down).
Indeed, talking of people not having played 4E but criticising it, that was a major drag in a lot of discussions about, because people frequently asserted opinions about AEDU or roles, or the like, without actually understanding how they worked, so you'd get these massive tangents where you were trying to explain to someone how AEDU actually worked. The worst was when you got someone who'd never played 4E or WoW, but was insisting, for example, that Defenders in 4E functioned mechanically nigh-identically to Tanks in WoW. And I do mean they were literally insisting that the mechanics themselves were similar, not that the end result was (which it wasn't, but that's another story). This didn't happen just once, either, but a lot of times.
This is part of why I'm disinclined to attempt to explain things in detail to people who don't want to make any effort to learn about stuff themselves, but want to argue about it. Several times I spent a lot of effort explaining the massive difference in approach and functionality between the Defender's ability to punish people for hitting his friends, and the monster-magnet rodeo-clown approach of MMO Tanks, with detailed explanations of the mechanics, and just got "Nah they're the same" or a similar response. In one case, I think on another board, I had a guy tell me I was lying and that 4E literally had a WoW-like "aggro" mechanic, but that was a lone nutter I think.
Yeah it's amazing how people will remember some false claim re: 4E, often an easily-disproven one re: mechanics, years later, and blithely repeat it as if it were gospel truth.
* = A much more nuanced and interesting thing was actually going on, which I think this clumsy assertion actually prevented proper discussion of, which was that WotC was hoping to make 4E fully playable online, and that having tablets/laptops at the table instead of character sheets would be desirable.
