I think that people are taking the (rather implicit) message in the article a bit too literally, and overlook the fact that it also takes interest to continue making music. There's simply no way to overcome the initial technical hurdles: they are quite big, although simpler for piano and guitar than for e.g. violin, and simpler for blues than for classical.

IMO, it's good to push your technical skills, but it's pointless if there's no internal reward. I happened to like classical music as a child, so I was frustrated when my first music school focussed on very simple arrangements of middle-of-the-road music. Switching to someone who taught (simple) Bach was much more rewarding, validating even. My parents did let me play whatever I felt like, though. I played my exercises, but also played popular music by ear (mainly for them, BTW).

So talent is one factor, which can be partially overcome by technical exercises, but interest in the music itself is what kept me playing.