Well… I'll splice in the word "temporarily." I don't mean the cuts the nerves off, I mean it steals the electrical signals so you don't lope off at a full run in your bedroom. Otherwise the device would have to wire directly into the core of your brain to find your thought-signals, interpret them, and then try to reproduce those thoughts as actions, but not the thoughts about doing, the though-moves. I guess that makes sense functionally, but that would require surgical implantation of neurocontacts that wire into specific parts of your brain to have physical contact with several of the nerves inside your brain. That means in order to play GenGame you would have to have extensive surgery in advance, and given how casually our characters have picked up the game, I wanted to try something that could still make sense without requiring multi-thousand dollar highly-invasive high-risk surgery. Even assuming medical technology is awesome for this, they'd be SHOVING METAL INTO YOUR BRAIN. Dude.
The most arguable point of a neurocontroller helmet that interrupts brain motor function to the rest of the body is that it would actually prevent motion in the rest of the body (proven non-occurring by SM) and that it's hella scary. I figured the hella scary was acceptable because this is GenCo, but I guess I do need to change that a bit to match the first few episodes "arrgh I can't stand" plotline.