Actually Kata can be very benifical to fighting, if you are doing the right Kata, and you understand what the Kata is training.
Problem is with so much of TMA that it has gotten watered down, function and purpose has been lost and people just go through the motions and not understanding the purpose of what they are doing.
Truth is Kata covers so many different things, power, breathing, focus, stancing, movement, technique etc all of which are directly applicable to fighting. But you have to do it right, and you have to understand what/why you are doing at much of that info is not taught or has been lost.
Undefeated in all of Asia!