I get the point of the post but, they are hosting a VPN service only to paying customers. they need /some/ way of linking an account to a customer, otherwise you can’t verify if who is using it actually paid for it.

yes they could just do like how mullvad does it, give a 1 off account number and if you lose the number you are SOL; but you need to look at FF’s general user base as well. they are trying to advertise this service to their casual userbase for privacy and anonymity while browsing the web. the path of least resistance is via the firefox account, that already likely exists for anyone already using the browser and is already tied into their eco system anyway.

also in my mind, if you don’t trust your VPN enough to have an account on it of some sort of throwaway identifier, you likely shouldn’t use that VPN in the first place. If when you go to sign up your first thought is “should i be giving this piece of info to this service” its not the service for you regardless if they later remedy it.