I don't really think that it's so much the lack of things to do, it's more that there's a longer gap between patches from the initial expansion release up until the first patch. Surely everyone remembers the 5 month gap between 3.0 and 3.1 which pretty much killed all momentum the expansion launch had? 4.0 to 4.1 feels pretty long too, even though in reality it's only 4 months, slightly longer than the usual gap between patches. But it only feels longer because the amount of things to do at Lv. 70 is currently pretty barebones, and thinking everyone wants to go level every job and pointing to that as 'SEE? THERE'S LOTS MORE TO DO' is a dangerous thing to assume from a community and a design standpoint. (For one, if people ACTUALLY did that, have fun with the DPS queues being even worse in theory.)
Probably the biggest irony is that while there's more content for raiders in theory, the way vertical progression works in this game is that raiders actually have less incentive to stay subbed late during the usual 6-7 month gearing cycle (since they'll gear up at an astronomically faster rate than non-raiders do), especially if they happen to clear the raid tier earlier. I'm not hardcore by any means (I still haven't cleared O4S), but I'm already item level 339 - and I spent half of the patch without a static. This is contrasted to the fact that I spent much of 3.x avoiding Savage up until 3.4, where I pretty much never finished gearing up until the next gearing cycle was released. And no, arguing that such people should gear alternate classes is arguing for content that doesn't exist, and encouraging bloat for no real reason at all.
To me personally, my biggest criticism of the 4.0 launch was that it was released without Alliance roulette. I enjoy the 24-man raids more than anything else in this game, but now we're in a 3 month lull where nobody is running them because at this point, the only reward in doing so is glamour. Even if you want to run them now, they pretty much never pop. I'm also a bit miffed that their sole reason for existing even when they're the hot new content of the patch is only to act as catch-up content for gearing.