With the less distribution of the SBD, selling of SBD will be challening because you can't accumulate it in lot like before.

So there is a benefit attached to community.

More STEEM means there is more power, you can give back more and if you need to withdraw - you need to wait for a long time. Which adds value back to the community.

As I see it - you can't be selfish in the long-term. The alternative is being generous.