One issue is that the current gatekeepers (peer reviewers for journals, grant proposal scoring committees, promotion committees, etc.) are often the people most prominent in their field. On one hand this makes sense for obvious reasons (an expert is the most equipped to judge their field), but on the other hand things like the amyloid hypothesis get 'baked-in' because, well, it's pretty hard to ask those same individuals to highly rank a large grant proposal that goes against their own theory.

So I think the answer is gatekeeping needs to be different -- not less.