Cars in the 35-45k range are routinely referred to colloquially as "luxury" cars. I agree you can quibble with this terminology, but it is absolutely common to refer to these cars as luxury, albeit the absolute low end of luxury.
I didn’t even count the offerings from Japan which are even less.
Following your logic the model 3 isn’t a luxury car either.
[1]https://www.caranddriver.com/features/g15379432/small-entry-...
https://www.autocar.co.uk/car-news/best-cars/top-10-best-lux...
Edit: Sort of reminds me of the differences in defining "class" between the US and the UK :-)
Every sales graph I've ever seen has relatively cheap cars such as the Fiesta, Golf, Corsa, etc. at the top. Not big Mercedes or BMWs.
But people who want saloons and estate cars are largely buying from the three Germans, and not Japanese or Korean.
So in the USA, or at least in California they are very common. Part of their popularity is their fleet use makes them direct cheap in the used market, and they tend to be pretty reliable despite the complexity of two separate drive trains.
Personally I drive a cheap car. Average new car prices have gotten crazy high relative to median incomes, enabled by low interest long term financing. A lot of buyers are ending up overextended.
My volt was super expensive in 2011, but 8 years on it still drives like the day it came from the factory. Unlike my Jeep (which i love) that is only a year old and already has aches and pains and squeeks and of course, drinks gas like its going of style.
BTW, when people shop for cars, the purchase price isn't the TCO. How much fuel will you be using and how much maintenance will you dump into it?