Now part of the problem is we don’t know the average membership length, and it’s further complicated by the fact that the Tate brothers ran the ‘school’ like a pyramid scheme where enrolling another member earned you a kick-back (which is why so many random channels popped up a few years back sharing clips).
So pulling random numbers out of my arse, if the average membership period was ~6 months and they had ~30% operating expenses (servers, bandwidth, kickbacks etc.) they could have netted ~$168m from this scheme.
I too, share your self-loathing in my morals preventing me from exploiting these absolute morons.