I didn't see any actual complaint yet, nor any meaningful description of the main perceived defects. Did you? I'm not saying they don't exist, I just highlght that the actual motives are not stated and thus the explanation is totally insufficient.
On the other hand ... it's pretty damn too easy to produce a document in ms word that renders like crap on open/libre office, I see it happening all the time. The problem is never the content, but dumb and irrelevant formatting practices. Comparing MS to a global infection, it is hard to heal by acting on a single point. TFA actually hints at this: "Wenn die ganze Welt mit einem Standardprogramm arbeitet, dann ist es wichtig, dass wir auf dem gleichen System sind". Sad, but they might have a point there.
The other alleged flaw, that someone had to wait weeks to get mail delivered on his smartphone because some obscure special mail server had to be set up on linux is obviously absolute bullshit. This, if at all true, speaks of incompence, not of platform suitability. So, this whole issue really stinks.