I am not a big fan of the previous Devil May Cry games. I played the demo for DMC1 (way back in the day). I think the demo came with a Resident Evil game or something. I even ended up watching a friend play through most of the entire first game. It was cool, but I never got into it after that. I think I played the demo for DMC4 when a friend of mine was trying to convince me to get it. I remember thinking that the demo game-play felt very stilted and awkward. It didn't appeal to me. (Please don't jump all over me - just giving my honest opinion.)
Get the hell out.
He gives you an honest view and you say that. Even on my worst moods, I'd try to reason or say something to him. But not just tell him to get out. You really make DMC antis look real mature. But then again, most of the arguments to dislike the game aren't quite that thought out (complaining about Osiris' hitboxes and Arbiter's damage, or the "broken" parry, if you can even call it that). So I shouldn't expect so much when it comes to reasoning a viewpoint to your opponent.