Under proof of work you essentially end up "staking" money by buying ASICs/GPUs that take 9-12 months to break even. In general, miners are going to spend almost as much as the block reward, whether that's in hardware and electricity or in opportunity cost. http://www.truthcoin.info/blog/pow-cheapest/
And many people are "hodling" cryptocurrency as a long-term store of value anyway so presumably they aren't concerned with the velocity of money.