You're both right and wrong. You'd be surprised how much impact 100k people can have in national changes. The whole stop killing games initiative is a lot less and it's at least getting a little bit of buzz.
But the thing is you gotta do more than downvote on steam to do that. That's where you lose people. I'm sure many web devs here can attest to how much traffic is impacted by an extra click. Ironically, logging into a new website to fill out a form may be enough to kill so much momentum.