I actually think these kinds of systems are interesting, I wish the internet had something like that from the start to "rate" users and if every online service had a rating there would be way less trolling, hacking and cheating in games.
Of course it can be exploited and abused, but that applies to everything in life. That's not a good enough reason to not do something.
Of course it can be exploited and abused, but that applies to everything in life. That's not a good enough reason to not do something.