Kryptonia is a community site and it's where the community polices itself and and takes care of those trying to abuse the system and steal coins which is what is happening when people take coins without any intention on following through on the Task requirements.

Revoking is actually more important than people realise. It is not just a way to get coins back. Every time a person gets Revoked their reputation score drops. This is then an indicator to others that the person is not behaving as they should. Then Tasks can be created that can only be completed by people with a certain minimum reputation score. This will weed out those abusing the system.

People can also build up their own trusted networks within the community. Connections have been implemented which is where someone Follows you and you Follow them back. You can then do Tasks that only your Connections can complete and if someone doesn't do your Task you Unfollow them which breaks the Connection and they can't do your Tasks in the future.

DISCLOSURE: I am part of the SuperioCoin Core Team.