Yes, having to maintain an OS over multiple years without recurring revenue might be an issue indeed. On my side I wouldn't mind paying a subscription if the OS could respect my choices. But I guess it does not really make sense to provide a subscription that only a very small handful of people would pay.
(I wonder how subscriptions could handle multiple machines; today it often happens that people have multiple computers but subscription cost would quickly add up; I guess they could have different tiers with different allowed concurrent use count)
(I wonder how subscriptions could handle multiple machines; today it often happens that people have multiple computers but subscription cost would quickly add up; I guess they could have different tiers with different allowed concurrent use count)