Did Mozart start out writing convincing Classical music? Or did he have to work at it? EVERYBODY has to work at it. Whatever they write.
If you just plop the stuff out from day one, it will just be musical diarrhoea. It may take some a short time, others a long time. But there are things to be learned before one can write convincing music of any sort.
Bach tried to emulate Buxtehude and Vivaldi. Handel tried to emulate Corelli, Scarlatti, and anyone else that caught his fancy. He was a notorious plagiarist. Yet all of these people, with all their copying, eventually "found their own voices" within the scope of Baroque practice.
Really, this whole thing about "finding your own voice" is BS anyway. A person has independently taught himself to write music, is comfortably doing so, likes what he's doing, and does a good job of it too. Then some academic comes along and tells him that he needs to find his own way? Dude, he found his own way and now you're stepping in to tell him how he SHOULD do something he doesn't really want to do? Where's the individuality in THAT?
A show of nonconformity when you're not a nonconformist is a waste of your effort and of other people's time.