That is not the only employment law. Firing someone translates to a higher likelihood that they will seek revenge, and it is trivial to get the state to accomp

That is not the only employment law. Firing someone translates to a higher likelihood that they will seek revenge, and it is trivial to get the state to accomplish that (e.g. filing a false claim). This potential liability causes a lot of side effects, such as refusing to give references to former employees. Or ever asking any personal questions about any topics surrounding protected status.