It does not make any sense. Why "founding fathers" of Pakistan were insisting Sheikh Abdullah to join Muslim League? Why couldn't they allow to whatever party Shiekh Abullah stick to it as long as Kashmir became part of Pakistan, though autonomous?
"Founding Fathers" committed many mistakes. Instead of immediate working on democracy, it started to unify provinces without taking into consideration of diversity, language and culture. East Pakistan ultimately parted away due to same reason.
You can call them mistakes but those were matter of principals and our Founding Father was a man of principals. His rivals were using all negative technics and they were little successful with doing their criminal acts.