Interestingly, there was a positive correlation between the amount of reading done on the subject and the opinion that further study was in order. Professional researchers would be likely to lose interest if there were complete lack of credible data. This shows a surprisingly high level of potential interest that could be brought into the open if a proper professional structure could be provided. Scientists value their reputations more than anything, and the perceived danger of tainting one's hard won reputation by association with a disreputable activity is a major obstacle. There is also a kind of non-linear downward spiral.
Scientists are both very busy and put off by the appearance of much of ufology.
As a result most scientists never look at UFO evidence, which leads to their conclusion that there is no evidence. Two other obstacles are irrationality and paranoid claims. One cannot avoid the possibility that, as Vallee argues, the element of irrationality may be the actual key and purpose of the phenomenon so as to force a change in human consciousness. And this would be very difficult for science to deal with because it is at first glance a frontal assault on science itself. But consider the advent of quantum mechanics and relativity in the early 1900's.