If a pretty woman came up to me and offered me $30 to have unprotected sex with me, I may just take her up on it. heheHow do I "know"? Well it is very easy and you can do this at home. You ask guys that you know. If another guy walked up to you and said "I will give you $30 if you let me have unprotected sex with you". You see what their response is? I do not know where you live, so maybe they would say okay, or no thank you, and be on their way. My poll got different results. It was more things like "When my fist came out the back of his head, he would know my answer". So if it makes you feel better.... In Chicago, THEY WILL BE KNOCKED OUT and I KNOW THIS. Maybe in your area they will wink and smile. So I stand corrected. It is not hot air "here" it is pretty dead on.
Now, seriously, what you're arguing has nothing to do with syringes and needles, it has to do with homophobia and prostitution. If someone supplements their income, or affords their addiction, through prostitution, then address the addiction and the business of prostitution. However, do not endanger the greater community in the interim.
If a drug user uses dirty needles, he OR SHE may contract a disease (not merely HIV, but Hepatitis, viruses, bacterial infections, etc). It's bad enough they have an addiction, no need to cost the taxpayers more money by the expense of medical care for treating diseases/infections that could have easily been prevented had they used clean needles.
As to the notion of contracting a disease from participating in prostitution, it is shortsighted to examine only the prostitute and the john. You must also consider all the people who interact with the john, the peeps who are "NOT" predators (as you call them) and instead are in some way associated with the john, or the sometime-prostitute. The spread of disease is not selective, unlike your judgmental nature.
As to this whole predator label, perhaps there are a few predators in the mix, but it is generalizing to label them all as such, particularly considering that "prostitution" is not considered exploitative in many cultures. In the U.S., for the most part sex is considered wrong or sinful, with the selling of such even moreso. But the U.S. position is actually a minority position, not shared by the bulk of the world. In most of the world, sex is considered sex and can be deemed a commodity if you can sell it for a profit. And, in all things requiring physical contact, it is imperative protections are provided.
Addressing this further, just as boxers and wrestlers, nurses and police officers, physical contact can result in contraction of a disease during sport or work. They are subject to obtaining diseases/infections from people who have infections and should be protected. Provision of clean needles decreases the likelihood of obtaining said diseases.
Here's an example: I worked in a mental health facility for a time. Some of the patients would occasionally carry needles in their bags or person, and we would be tasked to inventory their items. Doing such sometimes subjected us to contact with such items, with needles --- used ones. Also, occasionally a patient (sometimes a person flying on drugs) would become out of control and staff would be tasked to restrain them. A few health practitioners and police officers obtained Hep-C or other diseases because of such contacts (needle- or injury during a takedown).
So, you still against providing clean needles?