I would be willing to bet that in the employee handbook it requires that nobody act in a nature that is contrary to the advancement of the company. This most certainly is, and is also likely easily cited as a lack of productivity of the employee while being paid by the company.
Illegal policies are not enforced by courts. For instance, forced arbitrarion clauses, no discussions of wages, non-disparagement (Does your company say you aren't allowed to say negative things about the company, whether online or otherwise? Again, this probably violates your right to discuss working conditions), confidential information (if it violates your right to discuss working conditions), or social media prohibitions (if the company social media policy says you aren't allowed to discuss or disparage the company in social media, that may well violate your right to complain about working conditions)
There are some protections for whistleblowers exposing illegal activity, yea, but these employees were not exposing illegal activity. They were complaining about his antics/politics.
At will employment. You can be fired anytime for any reason, and there's not much in the way of recourse. Though you also get to quit without notice at such a job.
At-will employment says you can be fired any time for any reason except reasons that are explicitly illegal. This would include, for instance, discrimination against a protected class; anything covered by whistleblower laws (FCPA, all the relevant Dodd-Frank whistleblower provisions); or for organizing a union. It doesn't appear to me that the employees in this case have a slam dunk legal case, given that their allegations mostly don't seem to line up with whistleblower protection laws and while they were collectively speaking as employees, they were not formally unionizing. There are likely other ways to pretextually fire people engaging in protected activities anyway. But the question isn't crazy, this is certainly adjacent to the kind of territory that could have some legal protection.
Suing a corporation is timely and costly; and even if they're at fault for an illegitimate termination, they will drag you to court and humiliate you in the public domain. In practice, this means they can and do operate with near impunity.
At-will employment laws aren't an equivalent tradeoff -- which is why they are very uncommon outside the United States -- but the alleged benefit of such an arrangement to an employee is two-fold:
1. In places where termination is for cause, termination often causes an employee not to have access to various government benefits
2. At-will employment likely encourages more hiring in the first place, so it's possible that with more restricted firing you'd never have gotten the job.
I do not feel these benefits make up for the drawbacks and do not favour at-will as an organizing principle for industrial relations. But I just figured it would make sense to at least say the apparent argument.
It should be mentioned here that "for cause" can be any number of things, including simply "attendence issues", which realistically can be any sickness of you or your children that aren't quite covered by FMLA. All this realistically takes is you plus your three young children getting influenza at different times in a span of two months. Or not working mandatory overtime due to child care issues.
Doesn't seem imbalanced to me. I can leave and take my labor to any other company tomorrow without obligations, covenants or restrictions (non-compete agreements notwithstanding). I prefer at-will employment. Perhaps low-skill or low-quality workers feel otherwise, but I'm confident in my ability to gain employment.
At-will, in a sane world, means that a company cannot fire an employee unless they severely disrupt business operations, but the employee can quit and recieve unemployment benefits.
But I don't trust you to understand basic human decency so let me communicate that in a way you can understand: goo goo ga gah, bllblblbbb goo goo ga gah.
