My dear child ( yes you are a child so don't bother complaining, my youngest is 12 years older than you). You, as I have said, are incredibly naïve. You have not long ago made a thread about how your cousin was bullied and you have now just said that that bullying is justified because you think it's fine for an instructor to stand in front of a student and punch/kick them in the stomach without them being able to defend themselves. How stupid do you think that is? How do you not see an instructor doing that to a student as bullying?
You learn to take hits when sparring, you learn what you can take, how to avoid it and how to dish it out. No one in their right mind stands and lets someone hit him, that is humiliation and the instructor who humiliates their students is a lousy instructor.
If you are being treated like this then leave, find a place that respects you and teaches true martial arts not a place where instructors and others feed their egos in this manner.