Indeed. The reputation system is better when it's anonymous. And the only reason that Staff can see who gave you rep is because if someone DOES leave a really inappropriate or flame-ish rep message, The giver of the rep can be held accountable for it.
If you could see who gave you rep, nothing stops you from giving them bad rep in return, thus starting a rep war. (This is why you have to give rep to 25 other people before being able to rep that person again) Or worse, a flame war could arise, and burn brightly in VMs and PMs as well as threads too.
Also, rep is something you earn. If PC didn't regulate how rep can be given, it'd be worse than it was the first time we had rep. Many people abused it and they had an insanely unfair amount of rep. (Way more than they ever deserved) because they'd just gather 10-20 friends and start a rep ring, spamming the rep system.
I dont think Rep Ringing is still allowed. I'm sure the staff would edit your rep and possibly infract you and take away your ability to give/receive rep. By now, Anyone who ISN'T a staff member and has more than 2-3 pips of rep (~200-300 points) probably has had their reputation checked by the staff.
I'm glad the staff finally got around to giving rep a second chance. It really IS a useful system when the proper checks and balances are in place to prevent it from being abused.