I would say it is. But that isnt to say fighters are easy to pick up. Trust me I only recently started playing and it is more the amount you need to be thinking about all at once when I was a welp distracted my inputs. It's an adaptability thing imho. Give him time and he will get the swing of it. it could be that he is mixing up the stick and d-pad? That often made me fail inputs.
Most people nowadays only play games where you just run, jump and shoot. They are used to controlling the camera angles more than the actions themselves, and have become accustomed to simply having a "kill stuff" button. Thus, their brains have a hard time with fighters, as they have to remember what buttons to use in what situation.