Steem currently has a circa 8.6% annual inflation. If a Steem Power holder is not entitled to any more than the 1.6% APR afforded to SP holders by the chain and no more by virtue of merely holding SP, it will be very hard to persuade anyone to power up their investment. It is much better for an investor looking for the best possible ROI to keep everything liquid to be able to time their trades optimally. It is good to remember that investors are absolutely vital. Without them our rewards might as well be Monopoly money.