That's kind of the point: it's absurd to expect an employee--who doesn't see either the same rewards or the same risks as founders--to be as passionate about the company as the founders are. I'd go further--it's not just absurd, but astoundingly stupid and naive. It demonstrates a profound lack of both reasoning ability and experience.

Nothing stops a founder from walking away. Plenty of founders sell their shares to investors/cofounders in order to cash out.

Boards are typically stacked in the founders favor, so any reduction in pay would be the founders own decision. Which makes sense, because they want to keep the company that they have significant equity in alive.

I think you're talking about a company where things are going well. I'm talking about one where they've gone badly, and the founder has lost most control.

If the founder has lost most control, they also have way less equity. So way less reason to stick around. If things are going that badly, dump the stock, and GTFO, same as the smart employees are likely to do.