It's a weird question. But it's how I know whether or not I can deliver value to that potential employee. At big companies, salary and benefits is usually the main "value" that they provide. So, in essence, they provide the higher comp package necessary to make up for the fact that an employee is not going to learn as much as they would at a smaller company. A small company or an early stage startup is full of opportunities to learn. If your goal is to start your own company someday, I can make sure you're leaning the things that will help you get there. If you want to be a race car driver, I don't have much for you.
Employment is a two-way agreement. It's true that employers have the upper hand because they typically represent 100% of that person's income. The employee, on the other hand, is 1/N of the workforce. Switching costs are also likely higher for the employee.
For many people, I would imagine that a transparent and honest assessment is preferred to a pretend make-believe world where we imagine that an employee will spend their entire career in one place.
I think this is a great question, that's honest about the nature of a skilled employee's relationship to an employer. I don't think it's at all about the employer pretending to care about the employee - it's a straightforward way to find out what the prospective employee wants (other than loads of money, which this employer doesn't have), so that the employer can try to offer it to them. It's classic SPIN selling.