MS's Arrogance is what got them here, funny how quickly people forget. Also, MS didn't make the Xbox One for the world, they made it for the US and have still lost 8 straight months of sales..
I think what´s generally referred to as MS arrogance should really be split into three topics that each need to be discussed separately:
(1) TV TV TV!
This I think was their major stumble. First of all TV isn´t as big of a draw in gaming anymore since streaming video is the new hot thing and everyone has Netflix support these days. More importantly though this sent the signal that MS are building a console for the US market as TV support basically only worked in a few countries. This I agree was a huge marketing failure on their behalf, but even then I think the biggest problem is the order in which the XBO was introduced. First impressions count and I have no idea who could think it was a good idea to introduce the console via this perspective. If they had talked TV as an afterthought later after the games and OS focused reveal the backlash would have been nowhere as bad.
(2) Digital Only Future!
This is probably the worst offender, but I think a major role in deflecting this was not just internet forums, but in particular retail in the form of GameStop who publicly put their stock in the PS4. Now as someone who loathes #1 I actually would have welcomed and preferred an all digital future. The original plan was a lot like Steam except more open. I still feel this will eventually happen for both Sony and MS, but it wasn´t the time yet.
(3) Kinect for Everyone!
The problem wasn´t really Kinect per se, it was forcing everyone to buy it and making it a part of the mandatory ecosystem. It´s a nice accessory and ok for some kinds of games, but that´s it. Without it XBO could have launched at price parity and without the GPU reservation the resolution gap wouldn´t have been as bad in the beginning either. Price was the deciding factor though and really widened the gap a lot more than the difference in GPU power.
There three combined gave Sony the gold standard "first to 10 million" situation. Momentum is really important in this industry. The Matthew-effect is strong. Despite making the right moves it´s going to be tough for MS to catch up now.
That being said, I think we´re seeing Sony starting to make the same kind of mistakes (stagnating, taking things for granted) now that they are dominating: weak OS support, lacklustre first party output and infrastructure issues. Competition is good for the industry. I don´t understand the argument of buying exclusivity is being bad for the industry - it´s just standard business.
Sony would do the same (and look at Destiny with its exclusive content) if could and needed to. It´s just that they are bleeding too much money overall and don´t really need to go this route right now. If MS catches up too much expect Sony to start buying timed exclusives as well. Nothing special or anti-consumer about it, just competition between ecosystem vendors.