Because it is illegal and there is absolutely a chance that if this wasn't a sting, that Kyle Snyder would have been soliciting prostitution from someone that was trafficked into the industry. He is participating in what is currently a very toxic exchange that often involves a party that is only "willing" due to fear of the repercussions if they don't.
I get what you're saying. If two consenting adults want to have sex with a monetary exchange, that should be legal.
However, soliciting a black market service that relies heavily on human trafficking to provide sex workers? Yes, I absolutely have a problem with that.
He shouldn't be excused because there should be a better system in place. He participated in what is currently a very dark and sad industry.
And that's only what I think of him and the crime.. the fact that he would do this while having a wife and two kids at home is where it becomes a real scumbag act.