This is perhaps the only time I've ever found myself agreeing with you, rainless.
I would not be surprised at all if we learn twenty years from now that your theory is exactly what is happening. And actually, it doesn't sound crazy at all. nVidia and AMD are CORPORATIONS. I don't mean corporations in the "bad" sense either. It is the corporation's job to
make money. It seems most of the people complaining about companies like Microsoft and Intel fail to realize that. It isn't nVidia's job to just barely turn in a profit for the owner, it is nVidia's job to make as much money as it (reasonably) can. Why should nVidia spend more money on RnD when it will only prevent them from selling more cards in the long run? Look at this from a reasonable angle. Which would you rather have, a profit of about $1m every year with technology nobody even needs, or upwards of $5bil a year with technology right alongside software?