It would greatly surprise me if a member of the Olympic men's volleyball team said "you don't really play volleyball." People at the top of their field are way more likely to say "that's great! Keep it up!" The same applies in our field. The really great programmers I have known don't play the "you are not a real programmer" game.
Correct, that would be rude. However, they wouldn't put me on their team. It's their right to have tryouts however they want to. As arbitrary as entrance exams seem, they are part of the culture, and if you don't fit in, you don't fit in. Move on, start your own company.
