Now, that is over, in California, anyway.
Well... CA has been working on strangling the aftermarket market for a long time... no more 2-strokes, no modded exhaust, and probably a zillion other things. They completely castrated the large truck market by not allowing older trucks without exhaust regen to get grandfathered in.
There is also another angle to this... and that is the vendors themselves. I work in the swimming pool industry, where the big 3 manufacturers have (finally) stopped letting nobodies sell their product for cheap on the internet without being a genuine retailer. It was killing the actual wholesalers, by undercutting their prices, and creating absolute havoc in the service industry where customers (the end users) would buy for cheap online, then want someone to put it in for them... and... here's the kicker... warrant it when it went bad. Those of us with any code of professionalism quit installing owner-supplied appliances because of it... and the manufacturers realized they were creating bad blood with their #1 ally... the service companies.
The helmet and accessory market is different, of course, but I'll bet protecting their legit distributors is what is driving this. Distributors get very testy over their particular areas... understandably. Trying to compete against the EU, for example, is not fair, and often vice versa.