I don't know why, but I was under the impression that the decision to disallow guests from viewing feedback had something to do with cases where an employer or something is doing a google search on a potential employee, and ends up here, "Biggest Shitboi on forum, Skemmd my Grandmum for 5,000 BTC", "Guy sucks, l0l" etc feedback.
It seems to me that you could still display everyone's DT score on their posts without actually allowing access to each individual's trust page.