power down = parasite? No
completely power down = no interest in Hive? 99% yes (in particular when HIVE value is low)
completely power down = no interest in support others? 100% yes
you also gotta factor in that some people may have to, for good or bad reasons, what's important then is to check if the rewards they receive are worth the value they bring to the chain.
I'm sure many would love more passive curation rewards and to build stake but not everyone is in a position to do so.
For instance I've sold a lot of hive to help fund and build tools and projects on hive and I don't think that's going to stop any time soon. Do I want to do that? Not really. Is it always with the idea that what I invest in will outperform hive or that I feel I have too much hive, also no, but some times you just have to.