We want to avoid the upvote/downvote wars that destroyed reddit. That's why ignoring bad content is our preferred route of action.

I care because I know there are many groups that want to silence or harm me and others because of who we support and our worldview.

Then why on Earth would you want a downvote?

On the second point, if users can recognize shill networks, they'd be less likely to vote positively on them.