My guess would be the big red X on airsoft related to insurance.
As long as the goggles are built to a standard and issued and sold to professionals and the like they can feel confident the chances of being sued for negligence for real or phony reasons are low.
Once they open a new door they have to decide if the cost of liability coverage and testing will exceed what the make off the new market
There are a lot of folks in grey world already using ESS so they have to wonder if this is worth the trouble.
For some products the cost of liability insurance that's built into the cost of the product is frankly ridiculous, and for something that's risky (being shot near the eyes?) they can't hand you $40 and a t-shirt if get hurt. Even the frivolous stuff costs plenty to deal with never mind an actual incident.