Like a case of broken windows [1]. One could argue if such wanton destruction of the Orangutan habitats wasn't occurring in the first place, then there'd be significantly less incidence of Orangutan prostitution.
The destruction is not only precipitating Orangutans destined for premature death available to the sex traffickers, it's also setting an example of total disregard for their lives on a massive scale. What harm is there in exploiting them briefly for profit before they die? (Not my position, but I can easily imagine that thought process being real for the traffickers.)
But I feel it's also fairly obvious that there are positive effects to demonstrating care and good hygiene in general. It promotes the same from others. To do the contrary, demonstrating carelessness and neglect, has the opposite effect.
<anecdata> This week I was hauling a trailer load of trash from a cabin I'm rehabbing out to the dump. One of my distant neighbors I hadn't met yet walked out to the street and flagged me down to introduce himself and have a chat.
In the course of the conversation, he asked where I was taking my load of trash. I replied "to the dumpsters at the community center", an appropriate place for disposal.
He indicated across the street to an abandoned, decrepit cabin, which is directly across the road from his property a sprawling ~20 acre complex. What he suggested surprised me considering the proximity to his own property. He said "You could just throw it in there, the owner doesn't care about the place."
I bit my tongue and continued on to the dumpster, with thoughts of broken windows circulating my mind. </anecdata>
It would certainly go a long way to help, though.
In Africa, for example, tourism has become a major economic force in many rural areas, with rare animals being central to the attraction. Since those communities are as tight-knit as they are in small villages anywhere, they have both the incentives and the means to stop individuals from undermining the local economy.