Medicine also isn't in the "we recommend it because there aren't many reasons against it" business. They neither recommended masks nor warned against them, but laid out the facts: "we don't (didn't) know. We're scrambling to get data. We'll let you know"
I'm honestly baffled that the concept of a trial is so alien to people, and that nobody seems to be capable of the tiny transference of recognising that masks are no different than a pill. I could come up with a possible reason Aspirin might work: maybe it's the fever that kills, Aspirin lowers it. The risk is known and rather small. Should medical science recommend everyone to take Aspirin? Does it seem entirely implausible that a significant number of people would say/think "It's not the best time for a wedding, but everyone has taken triple doses of Aspirin so it should be fine"