Why would people who want socialism vote for people maintaining capitalism? Why would you equate participating in bourgeois elections as an indicator of motivation of all political action?

There's ~40-50% of US potential voters who don't vote for various reasons- Living in a state where the results are almost guaranteed, being alienated from politics in general because of the distrust in our government as a whole, leftists who don't vote but are politically active in other ways, etc. There's also people who do vote because they feel like they have to vote against the worse choice. If only all this alienation and lesser-evilism and feeling ineffective politically could be siphoned into a mass movement that helps all of us. Capitalism cannot be "fixed" if a group of people who don't vote suddenly start voting. That's pure fantasy. But it seems people who believe this would rather hope for a fantasy situation than actually looking at reality and adjusting their strategy to make things better. Otherwise, you'll just delay necessary change and feel resentment toward people who couldn't convince you fast enough.