I don't like having the idea for advancing to higher levels in baseball.
I would think it would be really hard for a scout to give a recommendation, or a college coach to put recruiting money into a pitcher that doesn't use a fastball as their main pitch.
Now, I'm curious if you have an effective splitter how is your two-seamer.
Generally the two seamer is harder than the splitter and is more commonly used as a main pitch.
A big thing is that a hanging splitter is a bp fastball asking to get crushed.
Often a pitcher can and will get away with a mistake fastball because of velocity and movement.
It's essentially why scouts like 100mph a lot more than 90mph, you can make a lot more mistakes when your punching 3 digits than you can at 90, let alone 85mph.