The most important thing is that it helped millions of people get health insurance -- it's just convenient to ignore that fact when your candidate doesn't have any similarly beneficial legislation to run on in comparison.
You'll notice that a lot of the Sanders campaign is about tearing others down -- especially Democrats -- as that's the only way they can assert their worth against popular "moderate" candidates like Obama and Clinton.
Democrats won the last Congressional cycle by historic margins via moderate candidates but that interferes with their narrative, so they avoid that fact.
Conversely, progressive candidates largely crashed and burned as many have no political support whatsoever in many parts of America.
The focus now is to impose Sanders on the Democratic party by claiming progressives can do better, despite providing no evidence that this is true.