Interesting that they don't like the gameplay. I always have thought that WCIV had by far the best gameplay of any of the WC games, and certainly is lightyears better than anything LucasArts put out. The excellent AI was part of that, the flight dynamics made posible by afterburners and the ability to cloak in a Dragon was part of that, and expecuially the deadlier missiles.
I don't think it's as unusual as you believe. I personally hated WC4's gameplay - I believe it's the worst of the main series (counting the spin-offs, it's second-worst, beaten with a huge margin by Privateer 2). The deadly missiles in particular were awful, because they added a random feel to the combat, where you would get killed in one hit, and almost nothing you could do about it. In general, WC4 gave me the same vibe that these guys suggest - that someone wanted to artificially extend the game by making it harder.
The absence of cockpits didn't help either. The thing that bothered me the most, though - and it's odd that I've changed so much over the years, but still very much agree with my fifteen-years-younger self on this - is the comments you got after you died. The game's difficulty had been pointlessly ramped up since WC3... and on top of that, someone thought it was a good idea to throw insults at the player when he died? Definitely not a fan of that.
As for the LucasArts comparison... well, I don't think there's much point going there, but I will say this: afterburners are not some amazing feature that LucasArts just couldn't figure out. They intentionally rejected afterburners, because they wanted to create a different kind of experience - and they very much succeeded. To me, comparing X-Wing to Wing Commander and claiming that one has better gameplay than the other, is like arguing whether a bomber is better than a fighter. You can
prefer one over the other (I certainly prefer Wing Commander, though I like the X-Wing series a lot), but there's tons of people out there who will have the opposite preference, and the things you like in WC are precisely the things that make them prefer X-Wing. And by the way, notice that after X-Wing came out, Wing Commander tried to change its gameplay mid-stride to follow in X-Wing's footsetps: why else would WC3 introduce power management all of a sudden?