Hackers exploited Word flaw for months while Microsoft investigated

The strange "counterargument" I commonly see on HN to any suggestion that Microsoft closed source software could potentially be unsafe for use on an internet-connected computer is that the company has "improved" since some earlier 1990's/2000's time period.

Are these commenters suggesting that other, open source operating system choices have not also improved since that time period? Should one consider how much did each respective system need to improve?

(By "other, open source operating system choices", I mean the ones that were able to connect to the internet for years before Gates decided the www was something his company should be interested in and to copy the TCP/IP stack from an open source kernel into the Windows kernel).

Are there convincing arguments why Microsoft deserves special treatment compared to the open source alternatives, i.e., why their users should not be permitted to freely evaluate the Windows kernel or Office source code via the public web? Are there compelling reasons why MS users should not be allowed i.e. given the option to edit/remove source code they are uncomfortable with and recompile? Consider the effects of limiting the number of people who can find and fix defects in a product.

Does closed source status of Windows make Microsoft's software superior to the longstanding open source operating system alternatives?

It's kind of like when a very lazy person turns into a marathon runner. They made huge changes.

Microsoft managed to gain a monopoly (legally or illegally - doesn't matter) and has used it to illegally keep others out, and network effects now (and for the past 20 years) have been that "goodness" measure - technical mediocrity had been sufficient (although recently they have been doing a lot of excellent technical work since the horrible 2000's)

In every single field Microsoft has not been able to leverage their monopoly (e.g. Phones) they are not in a dominant position, even though in some they maintain a competitive one (Xbox one, c#, SQL server)

Doesn't this have a lot more to do with pre-installs, and the marketing power that comes with it?

Dell's XPS Linux line and the Asus EEE PC were/are both pretty popular with the average person, so far as I'm aware.

Most people feel Microsoft is managing security better than the main Linux-based operating systems do, in terms of auditing, coding standards, code reviews, and developer security education. (That doesn't mean that they're doing this better than each and every individual open source project.)

Some of the people agitating for giving Microsoft more credit about this have personally seen the results, as in-house or contracted developers or auditors.

It can be hard to make an apples-to-apples comparison about what this means for the security of deployed systems because people are potentially using the systems in different ways with kind of different attack surfaces. (For example, quite a few Windows desktop users may still be downloading unsigned binaries from HTTP sites, which Linux users would be less likely to do because of the prevalence of package managers -- though maybe some of those Linux users will do the curl | sh thing from an HTTP site too.)

I don't think that a typical open source project has improved to the extent that Microsoft has during this timeframe, though, again, it's hard to know exactly what to compare or how to compare it.