Why create a thread about this when you could have taken 10 seconds to report to a mod? Then he would have been banned.
Because if everyone did what you did, there would be tons of posts saying, Hey Look At The Spam PM I Just Got. We all know what spam is. Just delete it, report it, and move on. And yeah, threads like these are the SPAM of the forums. They serve no purpose other than giving attention to you and the spammer. p.s. Do you respond to your email spam? Then why respond to PM spam?
I myself like to read threads like this to know what going on behind the scene, I think its funny to see how stupid some people are. Why would I post it if i didnt find it interesting ? And I respond to PM spam because I like to annoy the PM spammers. They normally get annoyed when you are telling them about their sister and her dog and before they get banned they will answer you. I find that entertaining.