The paradox of tolerance is just one philosophy on free speech (well really, an argument against it). Personally I think it is too easy to abuse to be a useful guide. EVERYONE thinks they are tolerant and EVERYONE thinks their political opposition isn't, so if everyone subscribes to the idea of the paradox of tolerance you end up with the people with power always trying to suppress the opposition. For example conservatives literally refer to the left as "the intolerant left".