Well in my case I find the existence of powerplay adds some "life" to the galaxy, I like the idea of "hostile space", althoug I think this free-to-kill state should only exist when factions are in some kind of conflict state, and not all the time. I am still pledged, but I actually stopped doing anything really PP related, not out of anger or annoyance, just because I don't really want to ferry papers around over and over from and to the same systems... Maybe this would become more interesting if instead of carrying papers, more realistic objectives were created for each system like "bring metals to fortify defenses", or "bring medicine and food", or "destroy enemy combat vessels" to some system preparing / fortifying, something like that. It would be a way to participate in the powerplay mechanics in a more "realistic" way, without having to ditch all the other activities.
I know that i can go to other factions space and shoot traders for "merits", but I also do not find the "shoot random people" mechanic quite that interesting.
I would like that PP factions had different states of conflict or peace between them, that affected the "hostile" status. Maybe in the future, after all PP was just implemented, maybe it will become more interesting and be added a little more depth in the future.
But like I said, whatever brings a little extra life to the galaxy is good, even if I just end up just a spectator like in this case.