Prof, I was very much the same. On a certain level, yes it was filmic snobbery on my part, but I also didn't like the way that many films were panned and scanned. It was often very crudely done by the studios.
I think a combination of two main factors has done away with the option of being able to buy Full Screen. Firstly it's the move to widescreen tvs - CRT, LCD and plasma, which has happened over the last ten years - the by-product being the falling sales of Full screen(4:3) DVDs that you mention. After all, they're not full screen anymore for many people. The second is the fact that studios are looking to cut their costs all the time and the take up of Widescreen LCDs/plasmas has allowed them to do this. As soon as they see even a slight drop in the sales of Full Screen DVDs, which they undoubtedly have done, they'll look to streamline their production lines to cut costs or re-invest those savings in producing the hi-Def versions. It's that simple. Full Screen DVDs only really took off in the States anyway. The studios weren't really that interested in producing two different versions for every foreign territory, they were more interested in making sure the American market was taken care of. It would've cost them too much and would've become too complex an operation, which is why they often sold foreign distribution rights to other companies. They made some money and it saved them a few headaches, especially as it meant they often left the hard work and expense of doing conversions for other tv systems to other companies. The beauty of Blu-Ray for the studios is that they don't have to worry about the process of interlacing and pulldown systems anymore. They leave that to the hardware manufacturers. They just scan the film to make a HD master of the film at 1080p24hz(the native film speed) and then region lock the discs for different territories and/or sell the rights for someone else to do it.
Blu-Ray is still a niche format that hasn't really entered the mainstream. A handful of people wanting to watch all their films at 16:9 isn't going to influence the strategy of the studios at this moment. However, if it does go mainstream and the demand for it grows, then the studios might respond. The problem is that people buy Blu-Ray for the quality of the picture and there's no way they're willing to compromise that. So what's the solution? Well, BR is still a growing format and and if it is widely adopted, it's still a way off. By that time 100gb BR discs will probably be a bit more commonplace and that might give the studios the space to put two top quality versions of the film on one disc. It'll be either that or some kind of software on the discs that is pre-programmed to pan and scan the disc whilst you watch it. With players becoming more and more sophisticated, I can't see why they couldn't implement that at some stage if the demand became high enough. Believe me though, they're definitely not going to pay to have the film scanned twice so you may lose a bit of quality(resolution) along the way.