I think my friends' art is bad, in low quality.
Is there a problem with the art? Is it because of the drawing, or the subject?
For me it's difficult to accept that something can be good for everyone, but it's bad for me.
You don't have to like it just because your friends do. You can be honest without being rude.
I don't feel that it is very interesting to me.
You shouldn't feel pressured to like the same things as your friends. You can be kind about the art you don't like if he shows you and asks you opinion. Do you feel a bit jealous of him?