Most people don't have $40k to blow on quad nods in the first place. I'm from the US and several states don't have any regulations or some with certain restrictions to purchase NVGs (
barring California & Minnesota) though it restricts them to export or carry em outside the US. Certain high end ones like EOTech had a civilian restriction in the past (
unsure if it's still in place) since they don't want someone to reverse engineer.
Optics Planet site isn't even asking any out of the norm info to buy EOTech's PNVGs
You can see air-softers & hunters use NODs regularly. There are some restrictions like you can't own a full auto-rifle, suppressors, compensators etc and particular blue states like California or NY make it significantly harder to even get a CCW permit
I frequent the gun store to buy ball ammo (I own a Sig P365 Nitron) and the process to buy optics is easier because you don't even need to fill out an FFL form. I'll ask em this question during my next visit