Technically, the principal has always supposed to have been the instructional leader at a school, but now with budget cuts, many of their district support positions (curriculum developers, assistant principals, etc.) have been eliminated and the principals now have to take on that responsibility. Also, the principal is the one held accountable for AYP, so if I were a principal, I'd want my teachers and parents to know that I am the instructional leader, not just their firefighter or building problem solver.

More than anything, it's to help change a mindset.