Why is traditional grip so hard?
It's hard to play with a balanced sound with one hand held overhand and the other underhand. (The opposite grips have opposite ergonomics.) There are different amounts of flesh on each stick, which affects stick resonance and sound. The left hand has a much more limited range of motion when rotating the stick up.
Are traditional grips harder?
Traditional Grip Cons: Harder to keep both of your Right and Left hand sounding the same. Slightly more difficult to learn properly as it involves less common muscles and the motion is awkward to start out with. Harder to move around and play different drums.