Not arguing that point, only suggesting how a business can survive in face of such an attack.
I understand that for some businesses keeping each unit count under 50 might be the only option.
But consider that, first, this puts a limit on how big they can grow, because beyond 5-10 units the business as a whole becomes ungovernable. Some businesses want to grow big to attract large customers, secure large loans, etc. They will have to foreclose on these opportunities by breaking up.
Second, that may expose them to other charges, for example, that the breakup is only for the purposes of evading the law. Obamacare is not the only law with small business exemptions; there are various regulatory obligations that kick in beyond 50 employees. They get a huge legal exposure if they break up without creating truly independent units.
Finally, if this law passes legal scrutiny in principle, the matter to adjust the employee limit downward becomes trivial. Soon, they will have to break up again.
Their real morally acceptable options are fight, sell or liquidate.