That would be what the REAL Saurfang would have done. Not this Alliance boot-licker. Cairne challenged Garrosh without giving a crap about anything else and his death counted to the turning of the Horde against Garrosh.
But I suppose they couldn't just copy Garrosh's villain story down to the last details, still it would have made a better story than what this abomination that is called Saurfang has been turned into.