The ability to write a short story is notably different from that of a novelist. In sporting terms, one is a sprint, the other, a marathon. They are as different as lyrics and poetry, and very rarely will you find the best of one is the best of the other (e.g. Leonard Cohen). A poet may be tempted to write music, because there's a lot more money in music, but that in itself should not be sufficient cause to ignore your natural talent and inclination. Some of the finest short story writers have never written a novel, or at least, if they have, not to the same acclaim. This group includes Alice Munro (Nobel winner), Raymond Carver, Chekhov, Saki, and O. Henry. To quote Munro:
"So why do I like to write short stories? Well, I certainly didn't intend to. I was going to write a novel. And still! I still come up with ideas for novels. And I even start novels. But something happens to them. They break up. [...] So I wrote in bits and pieces with a limited time expectation. Perhaps I got used to thinking of my material in terms of things that worked that way." (Emphasis mine.) -- Alice Munro (The Atlantic)
Writing is always a question of experience. If Munro had spent years focused on writing novels, perhaps she would have become a novelist. The demands on her time by her family didn't allow for the requisite concentration. Ultimately, if it's your desire to write novels, and you have the time, skill, and dedication, you should follow your instinct. Not because novels are more commercially viable, or because they are seen as great works of art, but because you want to, because great writing can only happen at the convergence of desire, action, and inspiration.