this makes no sense at all. if the interest rate for powered up Steem Power is to fall what's the point of powering up? might as well leave it powered down.
you're saying in 1 month the SP interest rate already fell 15%...and it will fall to 0 soon? who's deciding this? the deal was always if you powered up you'd get a a return in Steem..
Steem is already unattracive as it is as only buying a huge amount can actually bring you in the curation game. for the smaller investor powering up interest rate was the only attractive proposition.
the problem with Steem price is the ones powering down not the ones who keep powered up. if anything all interest should be removed immediately from those powering down (for some reason they still receive interest).