Because demand isn't the issue. The issue is a new car that isn't a budget brand is increasingly a luxury option in the United States, because, and say it with me...
Wages have been stagnant in the United States for nearly 50 years.
Every economic stat right now points to this as the core issue. Consumers are squeezed more on every last good and service, tons of services are now only available via subscriptions which inherently cost more, and despite the economy supposedly (and, actually) booming in a lot of ways, that doesn't hardly at all make it's way down to the workers either via higher wages, or via cheaper products.
This is a complicated situation that doesn't lend itself well to comments but a number of the bigger datapoints include an employment market that favored employers for the majority of the time since the 70's, the ongoing slandering not to mention outright interference on the part of employers against labor organizing, "inflation" that when you scratch the surface is just companies charging more because they can, the ongoing consolidation of enterprise resulting in monolithic companies that own dozens of brands of the same product, none of which truly compete on price, on and on and on.
There are a ton of good reasons for Americans to be broke, and a number of prominent economists have been ringing alarm bells for decades now that all of these things coming together is going to stall the economy cold and send us into the... by my count, fourth once-in-a-lifetime economic crisis I've experienced.