It seems that these are workarounds for providing selective regen in a car.
With Tesla's pedal design and the Brammo (and Zero?) grip design you get regen as you release the control, but this means that coasting requires maintaining a particular constant pressure on the control. That's fine for short periods, but long periods of coasting can get tiring. (With the Empulse you can use the clutch as well, but that also uses energy for long periods of coasting.)
With a motorcycle twist grip you can have both pull and push actions (due to "gripping" the control rather than resting on and pushing against it) so that you can set it up so that coasting happens at the rest point and regen is chosen by pushing on it, but you can't do that in a car and people keep saying that there is a patent for doing that with a twist grip that manufacturers are trying to avoid.
With a car, there is no "pulling" on the pedal in the first place so if you want totally optional regen then you can tie the selective regen into the brakes or you need another control for coasting. I believe that Prius does tie regen into the brakes, but I don't think you get pure regen that way and it adds complexity into a safety mechanism that should otherwise be very simple and foolproof. These cars are using an existing standard car control (steering wheel shifters) to repurpose them for selective regen.
Personally, I'm happy with the "release partially to get regen" concept. It ties into existing expectations of engine braking and simplifies the controls. My need for coasting is rare.
I'm not sure cars are getting boring, the dynamic behaviors on that Mercedes seem pretty exciting to me...
(Of course, I'm already driving a torque vectoring car - Acura's SH-AWD - though it is not nearly as sophisticated as the Mercedes mechanism.)
