Just like I said it in the title, Sony needs to stand their ground as the market leader FOR CONSOLES. Microsoft has never truly been all about consoles and they are starting to show their true colors. It doesnt matter how close consoles are getting to PC's, the console needs to be an experience that is seldom allowed to share its space with PC. If Sony gave their exclusives to PC during the PS3 era it would've been the biggest cop out. If Sony would've given up their amazing exclusives lineup to PC, they would never have caught up to Microsoft by the end of last gen. Microsoft gave up too easily and revealed who they truly are. Its known that they were never a great console developer, but at this point its safe to say that PC gamers are going to be gaming on console gamers dime with live for a good long while.
My reason for saying this is because is Sony goes open platform, they are giving Microsoft what they crave, which is less incentive for people to buy consoles based on who their friends are doing. It might seem like what Microsoft is doing is pro consumer at first glance, but in truth if Sony goes through with it, this is one less reason to to buy to go with the more dominant choice. Microsoft showed Sony zero quarter in this respect last gen, but do you really believe Sony should open up?