Why do you think that theory and practice are the same? For me and many other guitar players who learned from tabs, there's zero theory involved. Just mechanically learning a song through positioning and timing. You can learn considerable musicality and expression through this approach without ever knowing a word of theory.
My bad, I am mixing metaphors here. I meant 'theory' as in 'the opposite of practice or experiment', not music theory. I totally agree that there are many famous and accomplished musicians who don't know any formal theory or reading notation.