Why would it be illegal to express an opinion?

Yes, sadly, there is nothing illegal about being a giant pile of <moderators will ban me for continuing this sentence>.

Instead of suing, unionize and take a bit of the power we all ceded to the hedge fund managers back. It won't make things perfect, but at least you'll have federal protections and Weingarten rights and the like and the ability to push back and have the tiniest bit of power in your work place.