Part of it is a cost thing. Automotive grade buttons are really, really expensive. Honda probably pays $1-10 each for a button or rotary dial, a touchscreen is $30-70 depending on size. Plus, backup cameras are legally mandated, so they need to include a screen anyway, difference between a touch & plain screen is likely negligible, on the order of maybe $0-10. (costs are estimated and include the molding & plastics, which drive the cost way up).
I would imagine there is significant accounting pressure to push as much as they can onto the screen. There are definitely a contingent of designers who are upset by this trend, but I wouldn't be surprised if there is also a contingent of people in the design department who advocate for this due to the 'cleaner' look and are wanting to emulate Tesla.
Nearly all well intentioned laws have quite serious negative downstream effects, because the world is vastly more complicated and interconnected then commonly expected.
I would imagine there is significant accounting pressure to push as much as they can onto the screen. There are definitely a contingent of designers who are upset by this trend, but I wouldn't be surprised if there is also a contingent of people in the design department who advocate for this due to the 'cleaner' look and are wanting to emulate Tesla.