Why not return? Just because they don't want to or because they feel there's no need to return is irrelevant. They are employees and not employers. If some of the employees resign, they will be replaced with people who will comply with Apple.
Just so we're clear, I'm arguing in favor of Apple because they pay the employees' salary and should be able to dictate that its employees work in the office if they want.
As an employer, I'm not going to allow you to seek employment with my company and then dictate to me where and how you'll do your job.