If you are responsible for public health and the answer to the first question is "no" then you have no need to ask the other two. Figuring out what we can do to get people to do what works is important too, but it's not the only thing that matters. People can be educated and their habits changed.
We have similar problems getting schizophrenics to take their meds and getting communities with high rates of open defecation to use toilets, but nobody suggests that we give up on antipsychotics or sanitation facilities.
We have similar problems getting schizophrenics to take their meds and getting communities with high rates of open defecation to use toilets, but nobody suggests that we give up on antipsychotics or sanitation facilities.