What does consensus mean, exactly? It doesn't sound like Aβ-56 had full buy-in; the article mentions people complaining about an "amyloid mafia" and half of all

What does consensus mean, exactly? It doesn't sound like Aβ-56 had full buy-in; the article mentions people complaining about an "amyloid mafia" and half of all funding still going to alternate research, so clearly there were a lot of people who weren't part of whatever the "consensus" was. What's really interesting to me is that such vast sums can be spent, a number of people apparently did not like the Aβ*56 hypothesis and had substantial reason to oppose it or try to find holes in it with substantial rewards for doing so, yet the ones to find problems were some dudes (without any funding at all) just poking around.