I think a lot of people try a lot of things without success and become 'reticent' to try things after a while. The lack of success is likely due to the fact that this is complex and frequently requires things be approached in a certain way in order to succeed. People become hesitant after several failures and it takes a while for them to come around. The diminuation of mental capacities in many of these afflictions probably exacerbates that. I know I consider things very carefully and try to learn as much as I can about it before embarking on a new modality.
My .02. Not true for everyone, but it seems like many fall into that category.