Because TES VI will be console-exclusive for the Xbox. The take here is they cannot have it released towards the end of the generation when it won't matter anymore, as more and more people will be invested in PS5. The action plan, while brutal and will not go well with a lot of people, is actually quite a sound one.
TES VI
will be an Xbox exclusive? Have you got some proper inside sources or something? Because that's one of the most debated gaming topics atm and there's nothing definitive answer yet, no matter how hard you feel about it being so (FWIW I also think it'll be an Xbox console-exclusive as well, but there's good evidence and arguments to think otherwise, and jumping to conclusions like that is never a good thing).
Regarding the rest of the stuff you're saying, think about it a little bit harder. Why would you postpone supporting a very profitable game
now to work on a game that doesn't even have a public launch window? Not only would you be alienating developers who've worked hard on making Grounded as successful as it is today, but you'd be postponing profit now for probable profit later.
This is just a ridiculous take by someone who I assume is a reputable games journalist (at least if he works for IGN, aye?). I work in healthcare and even I can see that his argument is just completely ignorant and idiotic.