That is called the paradox of Tolerance. The tolerant cannot be tolerant of intolerance itself lest the intolerant will take over. So to maintain tolerance, intolerance cannot be tolerated.
Good point. It's the same with freedom. With absolute freedom there is no freedom. But certain ideological groups can't seem to get these simple concepts into their thick skulls.
If you demand respect or gratitude for your volunteer work, you're doing volunteering wrong.