The problem is, we were kind of expecting a variety of content or something different, not "2 dungeons to spam for 4-5 months", log on, do expert/cap, do alex, log off until Tuesday. You can tell that formula was already stale within 6 months of release, just by looking at the amount of people who had quit by then. If people were already quitting and taking long breaks (which isn't the goal of a mmo, the goal is to keep people playing every month) because of that, you can see why we were hoping it'd be more than 2.0 with dragons.
I don't know if this is your first mmo or not, but usually expansions for a mmo add something new and different alongside the current content, not just an almost exact copy of everything over the last year and a half. Congratulations, SE tricked all of us into paying 50.00 - 120.00 for the exact same content we get for "free" every 3-5 months. I can tell you, if 4.0 is more of 2.0, they'll start bleeding subs fast.
But... besides the zones, it didn't make it bigger. We have the exact same amount of content as we did in 2.0, especially since SE outdates stuff faster than its out for, there's pretty much no point in going back and doing coil or CT. That's another problem with how they're doing things, by 4.0, we'll have a massive amount of the game that's just dead and void of people doing the content (coil, hm primals, CT etc). If you think the whole "we can't add more inventory because the servers would crash" is bad now, wait until a massive portion of the game is outdated, empty and useless. All that data just sitting there, for nothing.