Also millennial. Also will buy everything except a Ford F550 in a manual transmission. Supercars and fast automatics are boring to me, I get enjoyment from involvement, much more so than acceleration or top speed. I think manual piques the millennial "instant gratification" need we are coded with, we won't wait for the auto to downshift when we floor it. Better to just drive in 1st or 2nd at 5krpm and gun it if a car with tint tries to saunter by.
Really though, I think it's no different than anything else. Some people prefer a Keurig K-cup Brewer, others prefer a filter in a basket that lets them choose their content. Scientifically, the portion provided with the K-cup is more commonly enjoyed. Some people still like 3 cups worth of grounds for their 14oz black coffee.
I'm sure there's a reason I still use a p38 for Spaghetti-O's that's the same reason I enjoy manual transmissions.