if I notice some constantly just powering down and never powering up - I don't think its strange that I don't feel like rewarding these users for their content as much as somebody else.
Absolutely. I do this too, and I also have a look at what's happening with the SBD, plus voting and commenting behaviour... and I absolutely make those things part of my decision to support a certain creator.
I respect the decision and the right to power down, but I would rather support people who power up. That way, by helping them, I am helping not only to build their stake but also that of the community as a whole.