I dunno... while I like the fact that I can read, and I'm still learning quite a bit... and looking at theory has been super helpful to me in the last couple of years...
the reason I didn't know more theory sooner has more to do with the fact that my gigs just didn't require that much theory.
Like, if I get a call for some blues or country gig, they ain't gonna have charts much less notated parts, and they don't want me to be creative, they want me to play the right parts, which more or less is always whatever notes I pick up off a recording or (more likely) something generic.
That said, I've taken up playing pedal steel and started playing a lot more piano just so I can understand enough theory to play the the steel effectively. That process has been super helpful to my overall grasp on music. And damn, playing with older musicians who really know some jazz is tough if you don't have at least a little bit of an idea of what is happening, even if you think you know the changes in one key.
It can be really fun and useful and inspiring to learn theory stuff. Like, tonight I've been trying to get some chords to substitute so I don't have to think as much when I'm playing guitar with this big band...
and I was playing C augmented on the piano and figured out that its the "same" as e aug and g# aug (though it's a B# and D

, which, dang I'm still amazed at the fact these notes have a real and intelligible meaning)...
that kind of stuff is super useful cause I don't have to think as much when I'm playing and I can think about something else like "holy crap what is that next chord even mean" when I'm sight reading. It's probably obvious to most folks who'd find it useful, but news to me.
So yay theory.
But my point is that most folks don't learn theory because they have enough of an idea of what is happening with the music that they don't need the theory, not because they worry about it stifling creativity. And I can't argue with not learning things if you don't find them useful. And to top it all off, it's damn frustrating and boring to try and get some theory down if you don't find it useful... I sure couldn't learn this stuff if I didn't have some other instruments to play where notes other than the major/min triad notes were in play on the instrument in typical generic day-to-day use.