Personally I think it henders the teaching of self defense techniques if taught in kata. Rather then teach self defense for a two hand frontal choke which we start to cover at 9th kyu throughout their training but not covered in kata until 3rd or 2nd Kyu and again at Nidan. Training against this tactic at 9th kyu by 4th kyu or at least 2nd kyu they have trained many effecttive counterattacks for this attack.

I think Kata are designed to store fighting principles and techniques not really apply them. Kata stores the techniques in its near perfect state. Application prepares the student for changes in the non perfect world of what ifs. By the time these techniques show up in our forms the student knows numerous ways to counter 100s of self defense scenarios. There priciples are strengthen by his/her understanding of Kata and how it applies to these situations.