I don't think anyone with even the slightest awareness of scientific philosophy or history actually thinks that though. Everyone knows that there are social factors involved to varying degrees in different fields, and that paradigms and research programs often only shift when the old guard in a field dies. The scientific method is a directional force guiding this messy social enterprise in the general direction of truth but if anyone thinks science as an institution is purely meritocratic they haven't thought about it hard enough or done the required reading.