Your anecdotal evidence vs. mine tells the opposite story. As an alliance player, I turned WM off while leveling despite the bonus, because it just wasn't worth it. I was constantly encountering 5+ man groups slaughtering people at the same or lower level along obvious questing paths and objective zones. It was not even close to being worth it, at 30%.
So, I guess I could ask you the same question. Am I, as a customer, less valuable as a customer because the opposite faction shits on me and blizzard allows it?
Let me answer. No. That's not how it works. I have to opt in to warmode, and if I do so, there is a known risk. On my particular shard, it's not worth it for alliance even at 30% and for horde it's basically a no-risk, zero inconvenience 10% bonus. Blizzard is not responsible for this, or "allowing" horde to shit on me and my leveling experience, and if I persist with WM-on, that's my call. That's the way the cookie crumbles.