Earlier quoted context omitted.
From where I'm sitting this looks like an excellent argument for breaking backwards compatibility. All those bullshit hacks are a maintenance and debugging burden for someone and a tax on the whole rest of the operating system -- and I'd argue that it really shows.
The thing about Microsoft is that they developed a framework for doing that kind of thing in a systematic way so it is not so hackish as it sounds. That's an innocent example but do recall that circa 1995-2005 or so, Microsoft looked like a dangerous monopolist and could have been in legal jeopardy if a product that competes with office (say WordPerfect) quit working when they went from Win 95 to Win 98 or Win 2k to…
Yes, people used undocumented functions, which were left undocumented as they were a subject to change, and accused Microsoft of not understanding software development or thought that those undocumented APIs were somehow better than the recommended documented ones. When stuff crushed after Microsoft changed an API people would be accusing them for deliberately breaking their applications and what not. I remember the hostility in those years 95-2005 towards Microsoft. There is still some cult in some Internet communities where trashing anything developed by Microsoft is seen as some kind of expertise or something by usually self-proclaimed experts.