Hiring illegals (knowingly) is morally bankrupt because:
- You are depressing wages in a given market.
- You are paying the workers less than the rate you would pay legal workers. (or else why would you do it)
- Your employees have no recourse to exploitation, no rights that can be enforced, no options. You can work them however hard you want under whatever conditions you want, because what are they going to do? Call the cops?
- You have an unfair competitive advantage against employers that don’t break the law.
- You aren’t paying payroll taxes, among other taxes, shifting more of the burden to the rest of the economy.
- You are an asshole who thinks it’s ok to weaken the economy overall so long as your get your piece of pie.

Honestly, it astounds me that this isn’t incredibly obvious to everyone.