This is an assumption based off the fact that we haven't seen many. I would strongly propose that had the 360 been initially relieased with a Blu-ray drive, the landscape would have been very different.
This is an assumption based on working in the industry and having to work with actual ingame art assets from leading studios. Everything is far, far more limited by runtime resources than by disk space. There's no use in shipping individual 4K textures for every object in a game world if you only have a total of 512MB RAM to display them.
But you're ignoring the fact that GTA4 for the most part certainly didn't have the very best image quality in it's cut-scenes.
GTA4 haven't had FMV cutscenes at all; and I've never seen any complaints about the quality of the speech or the music.
Contrast that with a game like MGS4 and Uncharted 2 whose dev teams weren't limted by the size of DVD, and it's clear as day how much more crisp and clean the cut-scenes for a game can be with a greater storage capacity.
MGS4 doesn't even use FMV, nor Uncharted 2 as far as I know.
And what the hell has FMV to do with
ingame graphics anyway??
When you look at multiplatform games, your perspective will automatically be marred by the fact that over half the publishers consumer base is limited by DVD capacity, therefore trying to argue that DVD is enough because "we haven't seen many games requiring more" is a pretty moot point.
There's always an option to ship the X360 version on two discs.
And we actually have seen games with content cuts on the X360 anyway - but it has never had any effect on ingame graphics, only on FMV and such stuff (like the TV shows on GTA4 that were slideshows on the 360 and FMV on the PS3 AFAIK).
Edit: also let us not ignore how most multiplatform games have reduced texture resolution on the
PS3.
It clearly demonstrates that the runtime storage (RAM) is a far bigger problem than the background storage (DVD vs BR).
The second bit about art budgets is something i'm not convinced of, and i don't really think one could make such a blanket statement.
Once again this is not a blanket statement, I have actual experience in 3D art asset production and my assumptions are based on this. What's the basis for yours?
After all ID wouldn't care to develop ID Tech 5 into a commericially available product license if they did not see as something that could benefit current game developers with current budgets.
Id's engine development is mostly driven by what Carmack finds interesting. There has never been any commercial need for the Doom3 tech back then, and I don't really expect Tech4 to score significant license deals either.
Afterall aren't most source art assets made for current gen videogames, of a higher quality than those seen in current gen games? Would it "cost" a dev/pub more to not have to compress their textures or reduce their assest quality as much as they currently do?
You clearly have no idea about the technical details of this question.