The whole point of E3 is to build up so much hype about your game/console people go out right after and drop that "60$" or in this case 500$ and buy it. If you can not sell your console after showing it at E3 how in the hell will you sell it release day. People can and have proven time and time again if they love something they will reserve it 9 times out of 10 in full price and wait for it to release. But if you have the PR that Microsoft has had you push people away and no one wants to buy it. The only event that is left is Gamescon and I don't even think Microsoft is in it "I could be wrong" So E3 was there last shot to "Sell" us the system so yes the bad PR will have a major effect on the sells of the console even tho they went back on a lot of there DRM.
Like for example Nintendo showed off some amazing games but also stated they wouldn't release until 2014 but the games they showed was so awesome "Like Mario Kart 8" people have went out and reserved it good chance in full price.
This was Microsoft's moment to do that and they bombed on it hard and are now trying to recover. If they really lissened to the gamer and not the numbers they would have open E3 with "We have removed the DRM here is your games" and may have even stole the show doing it. But that is not what they did sony beat them at E3 the numbers proved it and now Microsoft is trying to recover. I am not saying they can't but when you lose on the biggest gaming stage in a console war it has a really bad effect on your sells even more so when after the show you tell all your fans to go buy a last gen system if they don't like the new one. the same fans will tell Microsoft to go fuck themselfs and take that 300$ add 100$ to it and get a Ps4 over the Xbox 360.