Even reddit started doing this exact thing which you have suggested,

The only problem with this is that it can cause centralisation if not done right.

But yes, I think that its a very good idea, the earnings could be send to the steemit pool which can fund development and pay content creators even more money for their worthy content.

OP, you should inform the devs about this idea.

All in all, this would make the system much more sustainable in the long run.