100 something players for a game is a lot.
Less than 10 people I would consider dead.
100 isn't a lot for a multiplayer pvp game.
You're just going to be playing the same people again and again.
Sounds like it is missing enough content to hold player interest for now. It's a fair criticism.
I wouldn't buy/play a pvp shooter unless it had a regularly high-ish playercount (400-500+?), like TF2, Counter Strike, CoD, Halo, etc...
Also, 16 person servers is very small for a maximum. I normally expect at least one gamemode that can support 16v16 or bigger.