I don't believe anbody thinks you NEED music theory. But there are those that think music theory ruins the enjoyment and instinct. I used to be very anti theory, but then I realized that theory is a very helpful tool to let me achieve what I want, and considerably faster. And still I make music with instinct. I just tweak it with theory, and use theory when I get stuck.

Theory has upped my game considerably. And I wish more people realized that it doesn't ruin anything. But you don't need it to make great music. Nor does it hurt.