The existance of an infinite sequence of arguments whose union is fully-general doesn't mean that any given argument is.

Additionally, those counter-arguments aren't fully general. If you admit of some objective (or inter-subjective, or whatever; collectively accessible) standard of attractiveness, all of these counterarguments would be falsified by a positive correlation between attractiveness and saying feminist things.

This isn't to say that these counter-arguments aren't a bad idea for other reasons; we probably want some way of getting information from ugly people, for example.