That's the part I disagree with. Sony and Microsoft are working with the exact same partners to make their consoles. On the hardware side, MS has no advantage. They literally work with the same companies and simply have a small variation of the same hardware. (Both PS4 and Xbone have AMD 7000 GPU for example, but the PS4 has a more powerful version)
On the software side, MS currently have an advantage, but Sony now has the entire lifespan of the PS Neo to offer the exact same service. With the PS4 and Neo have the same games, Sony simply has to focus on the next console doing the same. So, Sony already offers backward compatibility between the two consoles (and they said players would be able to play some of the older games in better quality on the Neo), now they just need to make it work long-time instead of stopping at the Neo. It's not exactly the apocalypse.
As for games being easy to develop for PC/Xbox... True, but PS4 is easy too. That's actually why both the Xbone and PS4 are built like PCs, so that third-party developers could easily port their games to PC, by building games on the same hardware. (Instead of the clusterfuck that was the PS3 hardware, making ports a headache)
It's true that Microsoft is making it go from Easy to Easier, but it's not such a strong point when developers already have access to this. The relationship between the PC and the PS4 has actually grown over the past 2-3 years, with even more games making their way to PC. And with Sony going all-in on VR, and VR being closely tied to PC, I expect the PS4/PC relationship to remain strong.
I don't disagree that Microsoft isn't doing better in those areas than Sony, I only disagree that Sony is being left behind/has no plan to do the same. We basically have MS giving a 10/10 performance in both cases and Sony giving a 8/10 performance, while Sony also has a 3-4 years window to catch up to Microsoft before those mistakes start showing (when the Xbox 3 / PS6 releases).
Saying that those moves will lead to the end of the competition in the console world is quiiiiiite a stretch. MS is positioning themselves to equal Sony if they keep their hand strong. They're not positioning themselves to eliminate them from the gaming universe.