I bet they were taken quite aback by the Xbox One launch debacle. I and many others I assume were using their 360 as their entertainment hub already so it made sense to focus on that next time around. What they forgot though was that it only became the hub because of the games. They then shuttered all their good studios!

They also massively over-sold themselves on the online side. The dominant, 10m+ selling games on PS4 were all big single player adventure titles and this has continued. Tears of the Kingdom has done 20m copies in only 9 months! I look at my Xbox and I still see a 'shooter' console in an age where players are not interested.