Why is it important to study biomechanics of different sports?  Simple, to train them the right way.  If you don't know what your end goal is then its hard to create a great program.  Understanding how one pitches or hits can be crucial to their program.  For baseball its quite easy, the pitch is one of the most studied movement out there.  Check out this guest post on Eric Cressey's website for Albert Pujols swing biomechanics for an impressive read.