Yeah, but my understanding is that the manual issue is compounded by the fuel efficiency gains in newer automatic transmissions using these 8-speed designs, with minimum efficiency rules meaning it's impossible to match in a manual. I've noticed that in the handful of models still offering manual, often the manual is not offered with the top performance engine.
This seems to be happening in Europe as well where historically over 80% of cars have been sold with manual transmissions.
The other issue (at least in the US) is that automatic cars can be programmed to “game” the fuel economy tests by having shorter gears and shifting early, etc. The automatic winds up being faster and reporting better fuel economy, but the manual would perform the same if it had more similar gearing. (I heard recently that first gear is like 60% shorter in the automatic version of one of the BMW M series cars than the manual version.) Combined with engine auto stopping in automatics, etc., and it’s not really an equivalent comparison anymore.
Automatic transmissions now have 8, 9 or 10 gears which means that engines can spend more time in efficient parts of their range; I don't think people would put up with a manual transmission with that many gears. Newer automatic transmissions also have better control of lock-up, so that you're spending less time with torque-converter losses.
This seems to be happening in Europe as well where historically over 80% of cars have been sold with manual transmissions.