You are correct in that employers with scruples who treat their employees like human beings would be unlikely to litigate a non-compete. That is not who we are talking about. Think about why an anesthesia group would even have a non-compete clause. We don't have patients that we can take with us. We don't have trade secrets that will ruin a business if shared. An anesthesia non-compete doesn't make sense for traditional reasons.
Here's why they have a non-compete, using Charlotte as an example. AMC comes in and takes a hospital service contract from a private group (or buys out a private group). They get these contracts because they pitch that they can cover the contract without a subsidy and will save the hospital money. Their ability to lower or eliminate a subsidy is based on their preferential billing rates that they get due to their large size and ability to negotiate with insurers. They come in, cut MD/CRNA salaries (which is frequently tolerated in the case of a buyout cuz the docs got PAID), increase supervision ratios, and generally make the job worse. Now the job is worse and the employees start to get squirrely, especially after the contractually-required commitment from the "bought-out" docs. People start to retire, move away for different jobs, etc (but NOT work locally due to their non-competes). Now the AMC has trouble recruiting because the salaries have been cut and word gets around about how crummy the job is. So the job gets worse (more call, more supervision, etc without increasing pay), and now the AMC is having trouble covering its service commitments. The docs who have to stay local for family reasons or whatever are stuck because of their non-compete. Hospital gets fed up and wants a new group i n there. The real crux if the situation is that (especially in larger groups), there is no real alternative for the hospital to go with, becasue where are you going to find 100 docs in a market (like Charlotte) that just doesn't have them? The non-compete means that if the AMC loses the contract, all the employees currently working there are off-limits to the new group. It's kind of a "too big to fail" situation.
It's that fear of being unable to replace the current workforce in a reasonable timeframe (based on the enforced-to-the-death non-compete) that forces the hospital to keep working with the AMC no matter how bad things get. That is why AMCs non-competes are non-negotiable and will be enforced/litigated no matter what. Even if their non-compete is unenforceable, they avoid precedent by dropping the suit just before it goes to trial. Still costs the defendant almost as much time and money with no pesky precedent set.
The cases with Mednax in Charlotte and now Minneapolis represent how fed-up with AMCs hospitals are getting and the risks they are willing to incur (service disruptions, lack of coverage, toxic TV/radio/newspaper ads by the AMC) to stop dealing with them.