Now that's actually a really harsh thing to say. The content was released and ready to be done, people spent hours doing it and got rewarded for it. I agree it was not quite as hard as it would have been if implemented like it was on retail, nevertheless there was *still* a substantial amount of work involved in getting the Challenger Gold achievement (and mind you, some people even did every dungeon on multiple characters, like me).
Them handing out free CM gear to every alt, even those that didn't complete all the dungeons, was an accident that should get corrected if possible at all, but if you're going ahead and looking to wipe *all* CM progress thus far, you'd punish many players that did the content in good faith and actually worked for it to *some* extent.
Also based on your question regarding the removal of all previous rewards I'm assuming that you didn't actually complete all CM dungeons, so it's easy to ask the devs to wipe everything since you don't have much to lose. Others however spent hours of their lifetime on it, and seeing it all go down the drain would probably upset most of them.