The difference between Morata and Jese, aside from a different set of natural abilities is mentality. While Jese is a massive bitch and has nagged for a position on the team, which alerted Perez himself, he took his chances really well. Morata is a hot head, who I think has been playing in the wrong position at times (LW, lone striker) but he gets too worked up. He is an emotional player, whereas Jese is a lot more confident.
Morata's skills are not to be undermined either, he isn't as flashy as Jese but he is very strong, good in the air, and has shown great ability to work in tight space and more importantly, he is good in getting involved in the play in the final third. However, he works hard for the team and he needs to balance that with his duty of scoring goals. He will come good, but he needs a bit more self confidence.