The goalpost was set at "Linux succeeded and defeated Microsoft in every single way that matters to open source people". Ignore the record of what was actually claimed if you want (the quotes you're throwing around are works of your imagination), but that is not merely a claim that either Windows or Linux is "the most common".
The observation that that there exists some X where P does not hold is precisely the way to counter a claim that for all X, P is true.
To attempt to answer you (I might regret this): what did you take "every single way that matters to open source people" to mean? By gazing through your insults into your comment, trying to find the "∀x statement" you think you saw, I have to assume that you think that means "every one developing open source code isn't using Microsoft?" Is your made-up acquaintance working at a semiconductor company primarily developing open source software there (rather than, say, semiconductors)?
Is the "∀x statement" about "x: way that matter"? Am I to take "non-free software is being used for making semiconductor at a large company" as an example of something that should matter to open source people?
You seem so convinced that there is a logic statement written right there with quantifiers and everything that you don't hesitate to use ridicule on complete strangers and question their grasp of logic. It's funny but couldn't really count as an argument (assuming you were trying to argue rather than just get some bile out).
