Thats the most elitist, naive and untrue thuing I've ever heard.
Let's break it down.
Music theory, in it's truest form, is a set of rules defined by nothing less (and certainly nothing more) than aesthetics.
If we allow someone elses preferences concerning what sounds good and what doesn't dictate our own art, strictly because they are 'the rules', we've become less, much less, creative.
Again, a true musician does not require training or the ability to read music to understand and intrinsically use key changes, tempo changes, countermelodies, etc., to create the feeling they wish to convey with their given instrument.
In my band, there is one person with a degree in eastern music theory, one person who played violin in two symphonies, one who learned violin using the suzuki method, one with no training whatsoever, and the last, I don't know, and don't care, because he fucking rules his instrument.
We have absolutely no problem conveying what we need done within our group. The reason? We are all musicians. Not scholars. That's why we make music instead of study it.
To top it off, if you are going to write music using your theory instead of your ear, you ahd better know theory inside and fucking out, because you'll be missing all kinds of accidentals and modes that can make your music beautiful if you don't.
There is just so much wrong with your ideas here, I don't even know where to begin.

Let me add:
I believe Bach was possibly the greatest composer who ever lived, but I won't let peoples reliance on his compositions as theory dictate how I write if I hear something I like that doesn't jive with good ol' J.S.