Oh, I didn't know about the 3speak service. Thanks for pointing that out!
What I'm trying to say is that there are few reasons to power up right now because most upvotes don't require any SP as they come from all the projects like 3speak, Actifit, esteem,...
The difference in earning potential between starting a new account with 50SP or 10k SP lets say is totally neglectable nowadays since anyone can just grind out the free dapp upvotes and continuesly cash out giving few reasons to actually power up. Imagine that there would be SP requirements and time being active on the platform for the upvotes from all the dapps. That would give a real reason to power up and hold SP instead of being/coming to the platform just to earn (like most).
Wouldn't it make sense that someone who has been on Steem for over a year and is actually invested and powering up gets bigger Actifit upvotes for example compared to a new account with just enough SP to use the platform? Steemmonsters does this very good giving more DEC and card rewards to the ones who are invested more into the game. If this was the default way dapps gave out upvotes it would instantly cut a lot of the abuse and give actual incentives to hold Steem Power and be much more committed to this platform.