Because the game seems all but dead.

I haven't been playing for a few weeks now as there are (AFAIK) only 2 servers here in Asia and only one of them is active, but filled with hardcoe players.
So I go about looking for games on EU servers. But they too are few and far between.

I thought I'd check out online player stats. Here they are:
PC online: 783
PS3 online: 1321
360 online: 985

Heck, even BFBC2 has more players. MOHW has about the same no. online and it was worse than this. And let's not even start about BF3.

So is C3 a niche game or it just happened to die so fast? Just a week over two months since launch, no one seems to be playing.

There are ~10 topics about that. Please use the search next time.

It wouldn't be a niche title if Crytek knew how to make a real Crysis game.

Crytek's problem was actually that they had a very popular and loyal niche of players (3 million strong in Crysis 1 from one platform only), and then subsequently destroyed that niche in an attempt to appeal to everyone. So you end up with not appealing to many people at all, and the old popular niche abandons you.

Crysis 3 physical copies have sold ~1.13 million, across three platforms, with triple the budget. That is absolutely pathetic. EA doesn't report earnings until May 7 though so everything is estimates until then.

Crysis 3 a niche game? Hell no, not with all the simplifications they did to it. No bloody way.