Hmm ... I wouldn't logically conclude that. If I vote on an issue whose content I am critical of and largely disagree with, my vote on it would be taken as agreement in its external effect. I support freedom of speech by not allowing a negative consequence to follow that freedom of speech, so it is sufficient if I leave such content that I do not support unvoted, but do not penalise it either.

There is a clear difference between "allowing" and "approving". Allowing means that I do not put obstacles in the way of free speech. Approval means that I support speech that I do not personally favour with financial contributions or distribution of its content. Why should I do that? That would be like throwing water on the mill of a new regulation whose consequences I consider to be negative for me, for example.