I think your coach has painted with a very wide brush. There are colleges and MLB organizations who overuse pitchers but not all of them. There are colleges and MLB clubs that do a good job of teaching position players but not all of them.
Start with do you want a college education? How much will it cost a club to buy you out of that once in a lifetime opportunity? Then do your homework about the colleges and Mlb clubs.
They all have a history spend some time investigating. That will serve you much better than an overbroad generalization.