I don't think that Enterprise customers are the problem- they already use MS all the time. It's the small to medium size companies that aren't using it - and as they become larger companies it will become a problem for MS.
Exactly, we've been the bread and butter for Microsoft for a long time. Yet with Windows 8, we're starting to feel like that's just not true... at least that's the sentiment when I talk to some of my colleagues. For instance We built our main product using WPF, today WPF is all but discontinued. XAML is bigger then ever, but only if you want to make a windows store app.
If I leave .NET it's not going to be because some hipster writes an article about python, and how .NET is written by children writing kludge. I know that's not true. It'll be because Microsoft stopped doing the things that made me keep using them.
This is an interesting claim - WPF is still the main UI framework for writing Desktop apps, right? I don't know of any replacement framework that is preferred by MS for authoring desktop apps (I never use any WinStore apps on my Windows 8 devices).
So, not a flurry of cutting-edge development, but very much not deprecated either.
EDIT: Was finally able to get the page to load... I see the author alluded to this: "Yes, BizSpark is a great program for giving free Microsoft stuff to startups. It’s like a drug dealer giving free samples to get you hooked on their expensive and now compulsory wares."