Two immediate reasons... though there are many: (1) scientific materialism's fundamentalism which rivals that of conservative Christian evangelicalism and (2) job protection. If you have not already heard it, listen to Mark Gober's brilliant Where Is My Mind? series, the best podcast (imho) on psi research and the resistance it has faced— Gober interviews those university professors whose livelihood is threatened if they dare go near the topics. Thankfully we have the likes of Princeton, Duke, Cornell, UVA and a host of American universities who are moving ahead despite the rhetoric. Have not watched Hancock's series yet, but I will be doing so this week.