Well I'd assume the game is doing just fine even at the end of this year because those who bought the expansion without having played base-GW2 before, well those players will have plenty of stuff to do before they get anywhere close to being bored.

However I'd suspect that many of those who are complaining about the game's current status are GW2 veterans who have played the game since launch and are running out of things to do, that's not really that unusual. There's only so much game devs can put out before the content becomes stale or isn't enough for the player base.

However at least on my case I had been getting bored with the game's status months before HoT launched. There was a long period of time without any major new content before HoT was launched and I had hoped that HoT would have revitalised my enthusiasm towards the game. Well, I bought HoT and played it for few months and there just wasn't enough of content that I was interested in that'd keep me playing.

I doubt I'm the only one that experienced this. I was rather excited about the expansion but unlike the base GW2 that kept me busy for several months, HoT didn't quite have the amount of content to match that, nor did I expect it but perhaps it was even less than I had anticipated.

I don't really like how the new pve maps are based on timer based meta-events because that determines when I need to play which isn't suitable for my playstyle right now.

I'm also not that interested in the raids so for my taste the only repeatable content aside from the old pve maps are dungeons and fractals really. And dungeon rewards were nerfed and basically making it harder to find a random party to play with (because people are less interested in those cause of lower rewards).

Fractals got updated but not perhaps in the manner that many had hoped. Essentially it's still pretty much the same and because of that it's very much the old content we've had for a long time and everything gets stale eventually.

So all in all in my case it comes down to that I've already played the game for so long that the content that came with HoT just wasn't that much. Perhaps because it just wasn't to my taste (in sense of wanting to complete it over and over again) and I've already played through the old content many times. So the content that I'd like to play is just becoming stale. Hence why I'm on a break from the game, just no point in playing just for the sake of playing.

I doubt many of those who complain actually dislike the game in its core. I'd suspect that many of those who complain actually like the game and want it to become better in ways that'd make the game better for them. As for are veteran players leaving, who knows. I'd expect those that like raiding are excited about the upcoming raid wing and overall there's still stuff to do for many players. But on some cases, like on my case, it's starting to get a bit too stale.