There's a very slow, very week feedback loop that may be too weak at the moment to fight against this trend: the customers who are dealing with and worry about perpetual sensor failures and computer issues at 150,000 miles are not the same customers who are buying the car off the dealership lot. Meanwhile, the people with brand new vehicles are not worried about those problems, they're only slightly (and only long after it's too late) worried about the eventual resale value. I trust that my old Toyota and Subaru will still be dependable and repairable for many years, but I won't buy an old BMW or Mercedes because my family and coworkers have too many horror stories of expensive, exotic gadgets that have gone bad in mysterious ways.
But we're 40 years removed from the bad old days of the 80s and 90s when those imports were decimating the lethargic Big 3 in quality and cost, which is more like the time scale on which consumer attitudes like that began to be formed. 2018 laws regarding rearview cameras are really new in comparison to a cultural thing like that.
I think that implies nefariousness that probably isn't there. It's more likely a combination of:
1. Marketing/sales wanting whiz-bang features to use in their pitches.
2. Copycatting competitors, also for marketing/sales pitches.
3. Customers that are often not aware of the downsides, have been conditioned to accept them (e.g. they'll all like that now), or are uncritically enthusiastic about shiny new things.
4. Lazy design thinking, of the kind that causes Mozilla to drop good features from Firefox.
5. Cost cutting, of the kind that causes almost all companies to consistently choose to make their products marginally worse over time (e.g. lets not pay for feature X, since the users can use a cheaper awkward workaround instead).
Personally, I think we should have some federal standards for car UX: a required set of standard physical controls for commonly used standard functions (e.g. car operation, climate control, audio entertainment) and plus minimum standards for screen UIs (e.g. touch sensitivity & accuracy, UX latency, etc.).
While I'm wishing, cell modems and other data transmitters should be required to be separately fused, and that the car should be required to operate without annoying error messages if that fuse is pulled.