The show treated his attitude as a huge flaw. I interpreted his character in earlier seasons as despite being a genius in many ways, he was still an immature child. He was often ungrateful for his parents' sacrifices and unempathetic to those around him, like a lot of kids his age. He even had trouble making friends because others found him difficult to be around. As annoying as he could be, I think it also made him a more realistic character and set him up for later character development.