is Staff aware about this?
and it is now more than less earning platform for signature whores from third world, where they already have net access...
The staff can't really do anything about it (aside from "hunting" down signature campaign spammers, but this 'fight' has been going on for too long). The administration makes the decisions. I've even attempted to get signature campaign managers punished, but my attempt was obviously not successful. I'm pretty certain that most of the staff members are aware of the problem, the only difference is the stance that these members have towards the problem (some voice their opinion strongly, while others don't).
discussions and post quality significantly lost value over years (you can also see a difference, right?)
In some cases 'significantly lost value' is an understatement.