The trouble with that argument is that if you'd have asked anyone (anyone!), in any AI related field in 1980, where AI would be in thirty years what would they have said?
Surely not "Well, for instance one of the greatest achievements might be that we will work on chess algorithms, and we will see some incremental improvements resulting from tweaking certain heuristics and more intelligent pruning through more specialized algorithms and hardcoded chess knowledge. The programs still won't be able to learn in any interesting sense, but with the help of several orders of magnitude of hardware speed, they will be 200 ELO stronger than the best human!"
My point is that there IS no serious "pure" AI research these days. Your image of lots of pure AI researchers wasting their time is a fantasy-- those people don't exist. People work on applications.
The DARPA car racing thing seems to be a breakthrough. Granted, 30 years ago people would have expected more. But it is more than just a chess algorithm.
DARPA Grand Challenge? How's that a breakthrough in AI? Sure, it's uses a lot of results of "AI" research, but there's nothing revolutionary about that.
My understanding is that they made a big leap during the challenge - from catastrophic performance in the first run, to several successful drivers in the second run.
Revolutionary or not, I don't think it was trivial to make an autonomous vehicle.
Surely not "Well, for instance one of the greatest achievements might be that we will work on chess algorithms, and we will see some incremental improvements resulting from tweaking certain heuristics and more intelligent pruning through more specialized algorithms and hardcoded chess knowledge. The programs still won't be able to learn in any interesting sense, but with the help of several orders of magnitude of hardware speed, they will be 200 ELO stronger than the best human!"