If they're salaried and presumably stock comped employees they are being paid for their work. The flexibility to let go of employees is a double edged sword, but it's an important part of the U.S. economy. Without that ability, a risky endeavor would never be able to be undertaken. Companies would be way more leary of hiring more employees for fear of having to jump through bureaucratic hoops to let an employee go. In the meantime a company could suffer and ultimately die if not given the flexibility to evolve and adapt to changing market conditions.
A U.S. employee has to understand this. Nobody going to work at Tesla is unaware that the company is taking on multiple risks on multiple fronts and not all of them may pan out.
But I would argue that the American worker ultimately and on average benefits from the vibrant economy that such pro-business policies cultivate.