You are call is based on an assumption.
Its not the point that its an issue, I know it an issue for the devs. The PR bullshit part is blowing it out of proportion and the fact that this is news for the game. I could make a flash game that has uncompressed dolby 5.1 surround sound thats 50 gigs, does that mean its newsworthy? As knotter put it, its Kojima flexing his e-penis.
But the point is you dont know for sure if its done on purpose to irresponsibly fill up the disk just for the sakes of filling it up to use it in their PR. It sounds more like the case of having more flexibility and exploiting it. Even some developers on the 360 often mentioned that the DVDs sometimes create some issues they need to spend time solving. They manage to make their game at the end, but it affected the development. This shows that there is indeed a trend towards the use of more disk space. Because of that it is not strange to expect that the developers will use that extra space if its available to them.
In Heavenly Sword for example the developer admitted that the reason why they surpassed the dual layer DVD capacity wasnt simply the game content, but the HD videos of some of the cutscenes as well as the fact that it had lots of multilocalization which takes too much space since that includes sound(conversations and dialogs) and if I am not mistaken HD video cutscenes with the proper lip sync. It was an honest answer, nothing hyperbole or an effort to make us think ooooooo those beautiful graphics are attainable only on Blu Ray
For Uncharted they said that the storage has provided them with the freedom design the game without having to consider unnecessary issues revolving around disk space. The game could have been done on a DVD if they wanted to, but it would have had some changes in design which I find perfectly logical. If you know that you have some limitations you will design the game based on what you have.
I am extremely positive that if 360 had HD-DVD as a main format used for games a huge deal of developers would have taken advantage of that in their game design/development
I know it is food for the fanboys but then again everything is food for the fanboys. It doesnt make it PR though.