Massachusetts's state insurance used to be better than private insurance in most ways till a couple of years ago, when they started making cuts (the biggest of which was dental, which now only covers extractions and cleanings). Copays for masshealth are increasing, as are prescription costs, and it's need-based, so the people who are on it (presumably) can't afford the hikes (but, see below).
One of the downsides of masshealth vs. private insurance is masshealth pays less for the same services. So, some health professionals (doctors, psychiatrists, therapists, etc.) will refuse to take masshealth because they will receive less money for the same services for people with masshealth than people with private insurance. PLUS, people with masshealth do tend, on average, to be less reliable than people with private insurance (lower functioning, and also just plain less access to resources- ex. less likely to own their own cars and be able to reliably come in). Insurance doesn't pay health professionals when the clients don't show up.
Masshealth also has less stringent standards for who it pays. I could see masshealth clients when I only had my Master's. I couldn't start seeing private insurance clients till I was actually licensed.
The two above issues have a filter effect where some of the more esteemed doctors/"good doctors" are only accessible if you have private insurance. The neediest people end up getting a lower standard of care.
A caveat though is the issue of copays- masshealth has them, sure, but private insurance often has steeper copays. And if a health provider isn't getting the copay from the client, they're losing a big chunk of change there, too- and not everyone on private insurance can afford copays, either. If providers/provider companies want to survive, sometimes this ends up meaning turning needy people away because they don't have the money for copays. (We started doing this at my company a couple of years ago; we had not before, because it felt kinda wrong to do, but we needed to to stay afloat.) Sometimes we also have to turn people away because they fucked up on the paperwork for their insurance/it changed/it termed/the insurers themselves fucked up.
I get health insurance through my work (though I make little enough that I could be on masshealth if I wanted to). And it's good insurance. But, I do pay part of my salary to get it (it's not automatic), and there's a crazy-high deductible- I think it's $3,000 in-network, before the insurance company starts paying all the costs itself, though my company itself starts paying the deductable after I've shelled out $500 (though I end up paying more when non-covered medical expenses are taken into account). Since going from masshealth to private insurance, my medical expenses have become a non-negligible chunk of an increased cost of living, for me. It sucks. And a lot of employers are doing this (using a high deductable), to save money while still providing "good insurance."
One more thought: I have friends who live one state down, who don't have health insurance, and probably "should," and would if they lived in MA. However, the cost of living is much higher in MA, and I believe taxes are as well. I don't know how much of that is due to the healthcare, and I think that I'd rather have the healthcare, but then, I'm biased.
It's complicated, and by and large it's one big mess.
What is working black, lit?
Working without paying tax 
In the States we call it "working under the table," or "getting paid under the table." 
And it's practically a national sport 
Only way to survive if you're on welfare or social security (without having put a lot of years in- which, might I add, is incentive to work over the table, except social security may crap out before people in my generation reach retirement age)- needs to be supplemented, and that supplementing needs to be off the books. Which includes legal "under-the-table" jobs, or, more profitably, getting yourself a nice prescription for some fun meds and selling them. Depending on the med, you're gonna average between $5 (ex. bzos) and $30(ex. opiates)/pill. If you assume most rx's are 30 a month, for each fun-med rx, you're making between $150 and $900/month (more than some social security checks). And, often bzos are rx'ed 60 or 90/month- ads up to more than you'll get on cash assistance if you're receiving welfare/temporary disability. The system's fuckin'
borked, yo.
