Dan Schechtman, winner of the 2011 Nobel Prize in Chemistry for the discovery of quasi crystals, said:  “The main lesson that I have learned over time is that a good scientist is a humble and listening scientist and not one that is sure 100 percent in what he reads in the textbooks.” 

My research on groupoids and higher groupoids was started in the 1960s by a dissatisfaction with a van Kampen theorem that did not compute the fundamental group of the circle, a basic example: but groupoids were at the time regarded as "rubbish" by many senior mathematicians, and the idea of higher van Kampen theorems using higher groupoids was described   by one such for 10 years as "ridiculous". (He gave in eventually!) 

My worry is that people may be encouraged to follow high ups, rather than to analyse a programme on mathematical grounds,  and so to develop their own feeling for mathematical structures.