(as someone who was involved in WP fundraising a long time back, I guess I can comment)

There never really was such a time. Wikipedia has long had a razor focus on operating efficiently as possible, made extensive use of volunteer resources (even for sysadmin stuff, legal stuff, etc). At its inception Jimmy funded it out of pocket with the help of friends, but it wasn't very costly to operate when there was no traffic.

Six years ago Wikimedia had ~2 actual full-time employees (and they weren't paid much, at that— as they were just ex-volunteers). As the site has grown, costs have increased tremendously, but not linearly— but as Wikipedia has grown fundraising potential has grown too (though also not linearly).

Even way back in the old days Wikimedia would turn away 'support' that appeared to have compromising strings attached, people wanting feeds of private user data, etc. It's been very fortunate that it's never had to make the hard decisions.  Though back then there used to be a lot of speculation about what would happen if the money ran short— would we run ads to stay afloat?   Now adays, that prospect seems so unlikely that people in the organization can say things like "if our funding were to vanish, it means we are failing our mission. Public funding is an important check on our performance.".  (Easy to say when you're sure it won't happen!).

I think Wikimedia would accept Bitcoin today, except there is at least one important staff member who's fallen _hard_ for the "bitcoin is a ponzi scheme meme" (google erik moller bitcoin)— and there isn't any great justification for bitcoin for them enough to overcome that bias... after all, looking at what the EFF, FSF, and Internet archive have received... we're probably only talking about a couple thousand dollars in support from bitcoin compared to the costs of dealing with the logistics, a small risk of negative PR. It would really only be majorly worth doing for the sake of supporting something new and innovative.

I think that as time goes on, and bitcoin proves itself to be a painless and worthwhile fundraising source for other orgs that wikimedia listens to (E.g. the FSF and Internet Archive) then they'll probably come around.