I can't imagine anyone playing this game on a competitive level without using gyros. How are you supposed to aim while bunny hopping, for instance?
I'm sure that people will find a way to go pro-level without using gyros, each player has its own way to play and this is totally fine. Yet as you said, Splat Hopping and this kind of tech really look easier to pull off with gyros. (At least I managed to do it very easily during the last Test Fire)
I still stand my "Better fit in the game rather than make the game fit to you" opinion. Learning to use gyros feels much more rewarding right now... I don't think I could pull that Hat Trick again without Gyros since it helped so much at filling the gap between my aim and the enemy. In a nutshell, the right stick makes the big camera rotations then the gyro allows to do the little adjustments.