Are people not usually compassionate?

I am at art university, and I had a strange situation today. We had a nude model posing for us, a lady above 60. A guy that wasn't usually in our study came in and was washing brushes. She asked him to leave as she wasn't comfortable posing nude for someone who wasn't working with her right now. And long story short, he was incredibly insensitive to her and was just being a dick refusing to leave (she was quite cold too but honestly that's besides the point) even though it was time to start our model classes. And after all that I listened to what people thought. And mostly they were in agreement she was weird and overreacting. It made me so angry my head hurt. How hard is it to understand someone's boundaries? Our model is clearly a hurt person that went thought a lot in her life (she talks to us a lot), it makes me sad that people mock someone like this. Even after all those hours we spent with her they still feel her needs are not valid. I was the only person that stood up for her. Noone else bat an eye. I also put a curtain in front of the door to cover her when it was open. I feel sad to feel so much for others. Have you ever had situations where you felt you were the only one seeing someone hurt? It happens a lot to me