I don't know much about this particular group of people. A lot of what comes under the heading of psychology is bollocks and has failed to be replicated.
However, as a general principle, it is not a case of "We should base our policies on how the virus behaves, not how people behave"---you cannot separate the two things! Epidemiology requires a close and careful examination of social realities, how humans behave, what you can realistically get people to do and not do, as well as understanding the sort of stuff that you learn in a lab. These two aspects then need to be brought together to craft good policies and good messaging.
Take STI prevention, for example. Good STI prevention policies understand human behavior clearly, and connect this with knowledge about how pathogens work. Bad STI prevention policies are designed by people who have their head jammed inside a test tube and make no attempt to understand the realities of how humans behave.
Which is how you get things like "Sex spreads STIs, so let's tell the kids that they should abstain from sex until they get married, because if everyone did that there would be no STIs!" (Doesn't work. Very few people are realistically going to remain completely celibate until they marry at age 28 or whatever). Or "Condoms almost 100% prevent HIV transmission. So let's just keep nagging people in South Africa and Botswana that they need to use condoms and keep showering them with free condoms and condom campaigns and condom billboards!" (Only partially works. Most HIV in South Africa and Botswana etc. is spread through long-term relationships, in which it is virtually impossible to get couples using condoms consistently. Good HIV/AIDS policies in these countries put the emphasis on monogamy/fidelity, even more than on condom use.)