Well yes and no. If you are sparring then yes, you accept that you will get hit. Line drills however are a different thing. If your training partner doesn't block, does the wrong block, or has an ineffective block becasue they are new, then their partner should pull stop their punch. It's not a free pass to go hitting people in the face.I was honestly trying to hold back laughing because it's Karate, that is a place where people hit each other obviously.
It worries me that the instructor doesn't see that as a probem, and that you think it's funny.