I think 'bettering humanity with Windows' is open for debate. Some would argue that Windows, and the security problems it brought to the Internet, was the enabler for the single largest source of income for criminal enterprise outside of the drug trade.

Now it is much more nuanced than that, network based criminal activity has existed since the invention of the telegraph, but I would be willing to wager even on a per capita basis of Windows, Mac, UNIX, and 'other' users of the network, it stands out.

That said, those days are largely behind us (caveat Wannacry and poor update policies) and I consider properly patched operating systems from all of the major vendors to be credibly defended from exploitation. I reason to that point of view by using the price offered for 'zero days' as an indicator of the challenge of finding them.