There are highly placed researchers, people who've climbed the ladder over the years and have lots of authority in their field. They have their preferences about the direction the field should go in, and who should be doing the work, as well as protecting their own legacy.

Whether their reasons are benevolent or not, the existence of these people is the rule in science. If the knowledge moves too far forward, or away from their expertise they lose their relevance, and so they have incentive to protect it. This leads to biases in scientific research that are politically difficult to overcome.

Science advances one funeral at a time. -Max Planck