Right now if Steem Monsters signs up a new user they need to delegate SP so they have the resource credits to play. You need a decent amount of SP to have any results. With RC delegation they can just delegate the new user RC and no additional voting power. It is more sustainable and it also reduces abuse.
Once you have 1,000 or so SP you typically have more resource credits than you will ever use. As a whale you have a godly amount of resource credits. The only way to actually use them is to claim tokens. Everything else won’t even make a dent. But new users can’t do jack without a decent amount of Resource credits that only are available via SP