I agree with you, but what good is giving them the premium expensive food
if
they refuse to eat it?

It's hard to get them off of it. Years ago I used to feed Meow Mix. I finally
had to mix the stuff to get them started eating something better.

Will they eventually eat the good food if they get hungry enough, or be
stubborn and just starve themselves?

Some cats *will* starve themselves. They'll go without eating and put
themselves at risk of hepatic lipidosis. They're not like dogs. Especially
older, overweight cats *can't* go without food, it's risky for them. The trick
is to outsmart them. (As soon as I figure out how to do that, I'll let you know
:-)

Sherry