I think, the main point here is that Bungie have a lot on their plate. As such I don't believe that any version of Destiny is optimized for their relative platforms to the greatest extent. I don't want to undermine Bungie's teams, i'm sure the game has been optimized very well for each platform up to now. However, if Microsoft hadn't offered up their own engineers to uptake the responsibility of optimizing the game for the Xbox One, it would have released in its beta form at 900p even with the GPU resources freed.
Bungie just wants to develop a great game that runs well on all platforms, but that's all they are, game developers. They aren't a bunch of specialist genius engineers with the knowledge to optimize all systems to their fullest potential. They don't have the time or the resources to squeeze the absolute best performance out of every single aspect of every single task. If you glitch through some walls in Old Russia, you'll see the amount of out-of-sight objects that for some reason are rendered. It's just Bungie for you, man. It's not lazy, it's just how they do shit. If you don't like it then don't buy games made by Bungie.
Ideally Sony should have sent down some of its own engineers to help with the overhead, but it seems they did not. Why? Maybe because they, just like most people in this thread, believed the PS4 does everything on its own, just because it's 'more powerful'. No need for optimization. No need for man-power, resources, or the knowledge and experience of anything. It's just more powerful. It does it all. Nobody even needs to develop games for it. It does it itself. 1000x AA, flips its own switch. 4k, yup, auto-flip that switch. Dynamic lighting and shadows? Flip switch. Max everything, win at life, yup, maximum cannon switch, flipped. New motion control technology? Sleep until presentation is finished.
Microsoft made a good decision in sending down it's engineers. It means more Xbox One sales and more sales of Destiny on Xbox One. They were willing to contribute those resou
rces for a better product on their platform, and more sales in the long run. It's good for both parties. It's really nothing to do with parity or lazy developers. 900p to 1080p is not parity. That's how it would have been, that's how it was 'supposed' to be. You would all have liked it that way. But Microsoft said fuck this, here's our best, let them tinker, we have the extra 10% now and we'll do our best. We'll make it great for Xbox One, in turn making the Xbox One great. More sales for everyone!
If you want Destiny on PS4 to be the best it can be, you need to inform Sony to get their engineers over to Bungie and open up the book of tips and tricks, and lend their man-power and knowledge to an already over-stretched studio.