I don't think most people here are arguing against their capability to spend their money on whatever they want, rather pointing out that their doing so will even further such tendencies from Blizzard and eventually hurt the game substantially by making the same people pay even more for the content that should be "baseline". And let's not forget that very often paying for something results in regret much much later than the transaction occurred. I bet you my arm that most people did not even think this through, they were just bewildered by the possibility to get these items NOW, without having to do any grind or nothing. In short: they were the victims of marketing.
If you take all the people who spent their OWN money on these helms, you get a lot of people who have hurt the game and its future, further fueling Blizzard's intention of continuing with such malpractices.