You're also not taking into account all the players it helped. Before this exploit happened, Alexandrite supply was low and everyone that wanted to make a Mythic had to compete for what little supply was there. I have to imagine multiple players even bought from other servers because their server's supply didn't meet the demand. That shouldn't be happening.
But with this exploit happening, the supply rose and the idea of making a mythic became a reality for more people, especially with the prices (slowly) dropping. I can remember multiple instances where people were shouting to buy Alexandrite and competing with each other just so they would get to buy it instead of the other person. Once again, a supply problem that shouldn't be happening.