I agree that those who play the man as opposed to the ball are not contributing to 'reasoned' debate. Ad hominem arguments are a logical fallacy. However I would also say that those people who are willfully inflammatory in what they say are just as bad. Debate, like most things in life, is actually more constructive when both sides come from a position of mutual respect. I don't think Milo or his detractors, who you allege attack him rather then his argument, actually achieve anything productive in their debates when they come from purposefully antagonistic positions. To this end, I would question the motive for doing so, is it to actually further the debate, or is it simply to generate headlines, clicks and further ones own notoriety?
You assert that he backs up his opinions with data, facts, research and reasoning. That may be the case, but how selective is this data that he draws upon? How open is he to other points of view? Or rather is he simply focusing on what suits his arguments whilst ignoring that which doesn't? This is is the problem with data, it can easily be manipulated, taken out of context, or ignored to further your own particular agenda. "The Rags are XX games unbeaten in the league therefore this season is a success!" can easily be countered "Yeah, but they haven't moved from sixth in that time". You contend that he uses data to back his stance - then what does he do with regard to the overwhelming peer reviewed evidence which points to climate change being man made, which is counter to his opinion? Ignoring it does not exactly strike me as the actions of someone who is open to other points of view.
He goes out of his way to be inflammatory and to provoke his detractors, he is selective in his thinking, but most importantly he actually doesn't advance anything, apart from his own celebrity. A talking head who spouts sound bites aimed to pit people against each other, based on flawed reductionist logic, under the cult of personality of being a 'provocateur' or 'controversial figure' because he also likes to talk about how many cocks he's sucked. Give me a break. He's a bore.
A question I put to you - what has he actually achieved?