Walmart is not a person. It does not care one way or another. Not because it's evil, but because it's not a person. It can't care. About anything.
This entire "don't be evil" crap has really got to stop.
Corporations respond to incentives, not moral arguments.
If we, as a society, have decided that we want employers to completely provide for the health of their employees, that's fine. We should make laws requiring them to do so, with penalties in tow for non-compliance.
But please stop the entire "they just don't care!" crap. They're not supposed to. They're corporations, not people.
And yes, I know people run those corporations. Those people have fiduciary responsibilities to their stockholders, not to your moral compass. This is something resolved on a societal level, not on the corporate level.