I can see the possibility of delegating RC's to alleviate the problem that new users have (cant post, cant comment etc..), but right now they have delegated STEEM to take care of it.
Delegating RC's would be much more preferable and would release the STEEM. Hope that can happen soon.
Yes, Steem however is a voting token, RCs are not. Steem can draw on the pool, RCs can't really be abused other than what they allow in interaction. Because of this, RCs could have a zero undelegation time so getting them at the doorand on exit works. Pus, an application can set its own rules and remove RCs to curb activity if needed or use them as an incentive (depending on usecase)