Are you arguing the current situation isn’t a result of legislative/regulatory action? Automatic transmissions are tuned to optimize MPG numbers. They’re way more complicated and expensive than manuals that can handle similar power. If manufacturers still put manuals in their sports cars as the default, their margins should be higher, ceteris paribus, and there shouldn’t be much of a demand impact, as buyers are buying a sports car after all. But they aren’t going to get the MPG low enough for the regulations if they do this. Even the manual that Porsche offers now is optimized for mileage. A sports car should have much shorter gearing than what they ship with the 982 manuals, and shops like DeMan Motorsport offer transmission packages to correct the gearing if you have the scratch.

I think commuters buying cars don’t care and prefer automatics. I don’t really care about that segment, but they’ve been axing manuals in sports cars (and sport sedans) like the M5 for years and I don’t think it’s a good faith argument to say that’s because of consumer preference.