Earlier quoted context omitted.
They have a choice. An economic profit is defined as making enough profit (and intangible benefit) to not want to do something else. For a small business owner it's "am I better off selling it off and getting a regular job?" For a larger chain, it's "is there a more profitable line of business?"
This makes the assumption there is some kind of high margin business they can readily enter, but just don't for some reason.
No one just goes out of business; read a story about a failing business and there will invariably be a series of attempts they made to rethink their operation, failed acquisitions, etc.
So there we have to go back to the original argument: do they have a choice? I'm claiming their choice is the strategy they employ, they don't have control over the outcome, obviously.
The only case where you don't have a choice is when there's a sudden shock to your business; new laws put in place or something like mesothelioma crushing Lloyds. I don't think this applies because the changes we're talking about here are not sudden at all.
It's also not an all or nothing affair: you don't have to completely shut down one operation to start doing something else.
But other corporations can gradually enter and exit different lines of business, and this happens all the time.
Restaurant chains are a confusing example since they're really a mess of franchises. Even there, the parent corporation can create new branding and restauarant layout and effectively move into a new line of business.