Have you seen Horde players very much bothered by what happened to Theramore/ Teldrassil? No, because ‘Honor’ is different to them than to Alliance.
To them, ‘Honor’ is killing or being killed by an armed opponent, it’s a personal thing. If you’re ‘honorless’ for killing innocents, it’s not because it’s an evil act to be frowned upon, but because it’s a waste of time for your prowess progression/ combat exploits, etc. Perhaps you’re too coward to challenge more frequently, and someone may feel like punching you for that. But it’s generally your own business, not a big deal.
But an Alliance kills innocents, it becomes a big deal, it’s everyone’s business. ‘Honorless’ indicates this person has commited affronts to the whole ‘Honor’ system, the moral code. This is because ‘Honor’ is stricter Alliance side, you’re not only forbidden to kill innocents, you’re further required to protect them when possible.
At least this is my understanding, of why Horde players find Saurfang ‘howling for honor’ affected. I think they find Saurfang’s Honor more aligned to the Alliance’s one, not Orc’s.