Well, yeah. But the ROI shouldn't be from the voting and post payouts as far as an investor is concerned. It should be from (1) value of platform increasing, (2) possible "dividends", which already occur in the form of assigning interest to shareholders.
Participation is a separate matter, and I think it makes sense to separate the two. They can of course gain some from doing so, but they should follow the same etiquette as everyone else in thinking about the platform health as a whole.
I absolutely agree that anyone invested should be considering the platform's health as a whole. Unfortunately, some are in for the quick kill and don't seem to have the patience to wait for its overall value to increase. That's how it works in the real world too for some investors. Make a quick profit while it's possible and get out when the mainstream jump in.
It's beyond my knowledge, solutions to the problem of shark investors.