Why can't we play multiple games by gajin and earn gems?

It is impossible to earn gems from mutliple gajin games because your gamekit username must be excactly the same as the username of your proof. And you can't have the same username twice on 2 gajin account. So it is in fact literally impossible to get complete more than a gajin game. I hope someone is reading this and that this helped them.

would love to play and earn more gems :(

No it's not. I've completed both war thunder and crossout tasks. Your username doesn't have to be exactly the same. For example, I used MookGamer as one account and MookOnGames for the other one. Don't worry, it's entirely possible to get two gaijin games, if you don't believe me I think you can check my reward logs. (they're clogged up with golden gift card chests tho)

whoops

aha, I wonder why I got rejected then. I have when they don't give a reason. good to know anyways

hate*

Well gamehag take money for how many users do they provide for the company (in this case Gajin) so they are reworded for providing new users for every game. If you should use the same acc for every Gajin task- game, This will be 1 customer not for example 2 customers, that means less money for gamehag. So that's why you need to make another Gajin account. But every time you do this , be sure that you hit the play for free button on the right. The button from the task can give you an invalid account.

Good to know, thanks.