I cannot understand why this even allowed here. I mean, is this a game or something ? I can see everywhere downvoting questions and answers without a specific reason. I would like to see this stopped, please.

I would suggest either a massive loss of reputation when a user downvote a question or answer without a reason, or not allowed at all. 

Think about it(of course I speak about main AU, not meta) and be informed that a comment doesn't reveal who downvoted the specific question/answer. But this way we will avoid the lightly downvoting.