Different today perhaps but that doesn't change what it was back then. But that wasn't even the main issue. You had to actually kill Brutallus which was the initial gear check (that's assuming you could get enough competent people to kill the first boss).
Mechanics are still mechanics. One person could wipe the raid fairly easy on any boss in Sunwell, classes having more abilities doesn't change having that one idiot blow up the entire raid. I don't consider t4 or t5 TBC content, it was trivial... Hyjal/BT were also a joke comparatively but still had plenty of retard checks. Back then it was Sunwell or GTFO. Pretty sure that raid destroyed more guilds than anything before or after ever could (ok maybe the original Naxx would beg to differ).
I just said that things being grindy rather than skill based will have appealed to many players. If you want fast twitch uber co-ordinated team gaming you can play an FPS, after all.
Guild Blog for <Debonair> EU, Zenedar.