Actually, it is illegal to fire an employee for complaining that accommodations are not being made appropriately. That is a good way to find yourself in federal court as an employer and have to pay back salary.
If the employee doesn't stand up for themselves in these situations, and request the accommodations they need, or complain when the requested accommodations are not provided, employers continue to get away with violating the ADA and discriminating against employees with disabilities. The ADA laws are there to assist employees with disabilities. To not use them when you need to is silly. And it gives employers permission to ignore your needs.
