ok, you sucked me back in. You have valid points. I will admit that the HH is not as percise as an expression pedal, but the benefit to me is being able to move my hand faster than my foot. And I can still use an expression pedal at the same time. My first approach with it was like you are thinking, keep my hands free to work the bass, but that was more because the HH was moving or too sensitive with it on my hand. So I put it on the headstock and it works really well. I have moved it to my hand and have presets that activate it only when I want it. It's definately not for everyone, but it size is an advantage over a keyboard and I'm not seeing them as that similar like you are, sorry I just don't. But I totally understand your perception of it if you are only seeing these extreme techno videos using it. It doesn't all have to be synthy-techno, you can use it for anything an expression pedal can control.
There's very little that I despise more.