Second gripe is precisely its main selling point - that it can change based on context. I don't want my keyboard changing. I don't want to have to look down to operate my laptop, it breaks the flow and slows me down. I had 2 laptops with the Touch Bar. I tried every software for customising it. BTT, MTBMR (or whatever it's called), and at least one other. I always eventually fix them with the few buttons I use (no sliders): volume/mute, screen brightness, keyboard backlight.
Then, there's also the fact that you can't adjust its brightness or turn it off, and it's always emitting the full spectrum of light, which I find uncomfortable in the dark or late in the day. Granted, this is a smaller thing which is why it's at the bottom but it builds up the list of annoyances.
Edit: just remembered another one - it can freeze. Most of the time it can be fixed by killing a process. Other times, you need to reboot the computer.