Today we know that Milo Yiannopoulos is a very disturbed individual who has been involved in, and advocated, detestable things. That's why the Conservative Political Action Conference rightly revoked its invitation to him to speak. It also appears to have cost him his book deal with Simon & Schuster, and may cost him his job at Breitbart as well.
Tough stuff, but given what we now know about the guy, there is simply no defending him. (And if you're inclined to try, you might want to check this out first. If you're still inclined to try, please leave HermanCain.com.)
As to the larger question of whether Yiannopoulos's known opinions prior to this qualified him as a real conservative as opposed to some sort of alt-right provocateur, I'll just say this: Conservatives sometimes make the mistake of thinking that anyone who enrages the left must be their friend, and that more enraged the left is, the better the friend. Yeah. That's a mistake.