Hahaha, It's getting weird again.
As far as the manufacturers are concerned, the VGT program is purely adverting, nothing more. A PR exercise where the main thing that matters is the impact it can have upon the most people it can possibly influence. If they are no longer going to be released on PS3, they probably feel that impact and influence ship has sailed for GT6.
As far a PD are concerned, well they will have the back end numbers. If they don't release the cars on the PS3 they will probably feel there is no need to continue if indeed it is their call to do so. Without knowing the ins and outs of the partnerships with each manufacturers I don't think we can blame one side or the other.
Personally, I don't care either way and let's all be honest here, neither do many of you guys, it's just another angle to take a jab or praise good guy / bad guy PD to suit whatever stance you take. Grow up people.