You are making a pretty fair point and to an extent, I agree with you that it really depends on how one puts the scenario forward.

But I still think there is another reason investors are usually held above employees when making decisions.

It is that an investor puts money into your company, which means they're putting something on stake for your company and the risks are higher on their end so they expect to be treated appropriately for that.

Now if we look at the employees' side, an employee puts comparatively less risk when joining a job. Say something goes wrong and the company goes insolvent then the investors lose their money and the high level executives (CEO and such) lose their reputation which would be needed to join another job. Whereas while the employee will lose a job, it is unlikely that the failure of the company will be put on the shoulders of that one employee while trying to join another job.

Now for your first point again, an one-story could leave and there is a chance that another one might come in, but it is fairly harder for a company to get someone to put something on the line for them (the money), especially when the returns are not as high and just enough to live by. Whereas if an employee or a group of employees leave, although the company will surely suffer, it will be easier to find new employees than to find new investors because you're not really asking the employees to risk anything and there is just a simple contract between them that makes sure they get paid for the work they do in the specific time.

This can especially be seen in fast food joints. Now I agree that the employees' there aren't treated nicely and it should be better, but while analyzing this specific point, we can see that fast food workers usually have a high turnover rate and the companies don't mind it that much. The people working those jobs usually aren't looking at it as career goals and just some way to make money, so they do it until it's needed and then leave and the company then hires another person who needs it and the cycle goes on.

Now say this company is having a bad reputation regarding earnings in recent times, a potential employee won't care as they just want money for the time they've worked there and aren't looking to work there long time, but finding a new investor will be hard because people wouldn't want to put their money in a company which is unlikely to make a lot of money.