I can't speak for others than myself but to me exposure itself doesn't do anything to improve my social anxiety. The fact that I went to school almost every day for nine years and only got worse should be enough to prove that. Exposure can be of different kinds. If it's unsuccessful and you're humiliated and made to feel like a weirdo (which usually has been the case for me) it's only going to make matters worse. Exposure has to be neutral or positive.