Yeah, I wish I could be a psychotic, mass murdering, genocidal maniac. Oh sorry, I mean ex-psychotic, mass murdering, genocidal maniac.
The Orcs had free will and made their choices. They were not 'mind controlled', the best that can be said for them is that they were so stupid as to continue following their leaders without thinking for themselves even when given plenty of signs that something was up (wat the elements, our ancient allies, won't aid us in this? They must be wrong, it can't be us! Better go be warlocks instead! Hey now our ancestors aren't talking to us either! What's with that? Eh they must be having a bad day - week - month - year, it can't possibly be anything we're doing!).
For 90% of the war they were not even under the influence of demon blood, it was only something they consumed prior to the last battle at Shattrath. Saurfang himself was a general in the war, for the Blackrock clan and under Blackhand, one of the most notorious clans in terms of it's levels of violence and parallel atrocities it committed. Another powerful Blackrocks *chose* not to drink the blood and didn't buy the whole story that was put to the Orcs (see Orgim Doomhammer - although I'd equally consider him to be a war criminal as well, my point here is that the Blackrock leaders had free will and could exercise choice), Saurfang equally could have made that choice.
So what exactly has he actually *done* to atone for what he did to the Draenei? Where exactly has he expressed his regret in terms not entirely based on *himself*? He talks a good game, but actions speak louder than words, and he has never sought to make any sort of actual atonement for his crimes with the people he committed them against. If he's actually so innocent and remorseful then why don't you believe he should stand trial for crimes and accept actual consequences for his actions?
Boohoo he's sorry isn't really good enough. Citing being friends with humans in the context of both fighting the Lich King as him atoning to the Draenei doesn't make sense at all. You don't excuse war crimes based on nice things done to someone else entirely later.