Well that's actually not their fault
There is what is known as brand equity, don't know if you are familiar with it
Its like a kid knowing his dad as black and broad since he was born, and there is such a great bond between the child and his father. Then suddenly the father goes for a surgery, now he is white and narrow. He even changed his voice. Don't you think it will be difficult for the child to bond with his father.
But an improvement in their branding would be great. I guess maybe most of them think a rebrand only means a total change of who they are.
Something tells me NTA for example are just scared of moving on