This question was inspired from the Todd Sucherman dvd I recently watched. You know what, I’ve heard this nonsense for decades. It simply doesn’t stack up. A good drummer is a good drummer. A well educated drummer should still know when to and and when not to play certain things. It’s fine to be unschooled but when you stretch out your horizons you are only adding to your weaponry. You won’t lose anything you will just have more things to draw on, be more versatile and play with more ease.
To me the never ending journey of discovery is part of the charm of the instrument.