I believe that art, like anything, is a skill that must be cultivated in order to get “good” at it (recognizing that often times “good” art is incredibly subjective, and also recognizing that savantism is a real thing but rare and not really what we’re talking about, so we’re setting those devil’s advocate arguments aside for this answer). But I also believe that what folks call talent can possibly be defined as the love for the thing they are pursuing, which pushes them to work at it and do it often, which generates a high level of skill.
I really enjoy this 22 minute podcast from Radiolab about this very thing. In it, the Malcolm Gladwell says that "love is not the complete explanation, love is the way in." He continues on to use hockey player Wayne Gretzky as an example, that "because Wayne Gretzky loves hockey so much, he thinks about it all the time, and does more than that; he engages the sport in a way that no one else has ever engaged it." The whole podcast is worth listening to, as it explores the argument between talent and skill.
A person generally has to WORK at something to be good at it. I’ve worked really hard to get where I’m at, and I know other artists have worked really hard to get where they are. I wasn’t born with the innate ability to paint and draw like I do, but I have always loved creating art. Because I love it, I have done a lot of it. And because I do a lot of it, I have cultivated the skills needed to paint and draw and get “good” at it.
Which brings me to this… All artists feel the way your friend does sometimes. Some of us more often than others. But remind your friend that the skills he wants are not magically out of reach, they are attainable as long as he continues to LOVE what he is doing. I would never encourage someone to continue doing something they hate, or that makes them unhappy. Art is supposed to be fun! I very much hope he rediscovers what it is about creating art that he likes, and continues to have fun doing it. =)