Technically you are putting theory into practice, you just don't know how or why except that it sounds good.
This is basically the point. Most people's ears know music theory just because they've been exposed to so much music based on that theory their entire lives. So those people can happily make music and get really, really good at making music just with that 'ear theory'.
As I said before though, I think it gives most people a better chance of making great music if they understand at least the basics of music theory. If your brain understands the theory your ears figured out long ago, you open up some more possibilities, and lots of troubleshooting tools (the latter being the main benefit, in my eyes).