Why is Casey Jones even IN this version of TMNT?!

[Luckyday]

Hi! It's been a while.

Anyway, I thought his main reason for existence was act as a mouthpiece for the boys' target demographic? Even though he's much older, he's mentally a kid when reacting to situations that a older person or any sane person would be horrified by. A disturbed kid maybe but never less a kid who had been raise on tv monster movies.