Honestly, I think it's a bit rude. It might be junk to you, but maybe to others it isn't? How would you feel if someone saw a shirt you were wearing and said something like that? Would you talk to another adult like that? I don't know. I try to treat kids with respect and I can't imagine calling a childs toy junk. It is obviously a negative term. If the toy is important to someone , it's not junk.