I think a lot of this has to do with safety. I'm pretty sure the software/fb3 connection is constantly monitored at a specific performance level because the last thing you want is to lose data and have a stray beam hit someone. I could be wrong but that is what I would wager. As a rule of thumb, I never operate any show devices from a USB hub. That includes my Midi controller and my Enttec DMX controller along with all laser hardware. Too many things in the chain that can break down. When selecting a motherboard for my show machine, I made sure it had ample USB ports.
The other problem that I have seen is the proliferation of absolute garbage usb cables on Amazon and other sites. It's hard to find honest reviews and decent quality cables. Most of these are now just "good enough" bulk pack from China.
If you're the smartest person in the room, then you're in the wrong room.