Don't see the problem and never understood why so many have a problem with it in forums. Most console gamers don't play on PC (except maybe some smaller games like Hearthstone) and many PC gamers don't play on console.
Maybe 10-20% of Xbox players play big games like Gears also on PC. 80%+ have probably no PC or only a small Notebook or something like that.
There are also people who will find it good that they can have their gaming PC in some room and their XBO in their living room and have access to the same games with the same game saves and achievement.
So, MS's decision is maybe affecting 10% of Xbox players negative but for the other 90% of Xbox players, it isn't doing anything to them or it is better for them if that ensures higher game sales and more investments.
This is really not that hard to understand as long as you aren't one of these "I play on PC which means MS is stupid because they let me play the games there" people.
Will very few of you buy an PS4 instead of an XBO because you can play Xbox games on PC? Well, just do it, MS will still get your money then and be happy that you are on Windows 10 buying their games. Chance is probably pretty high that you would also buy a PS4 even if the MS games would be only on XBO and not PC.