The Albigensians believed that intentionally starving oneself to death and starving one's infant children to death were good things. They also believed that killing another person was an act of mercy, since physical reality reality was evil - that the world was created by the Devil instead of God. They were a death cult similar to the Solar Temple or Aum Shinryko.
The fact that Albigensianism stopped spreading was a very positive development for the human race.
You won't find the Catholic Encyclopedia saying that the Spanish Inquisition was a good thing just because it kept Spain Catholic. The Catholic Encyclopedia realizes that the Spanish Inquisition was an egregious example of the abuse of power, while the Albigensian example was a matter of civilization fighting for its life.
As for the factor of ten, try a factor of a thousand. There are people who will claim with a straight face that 100,000,000 people instead of 6,000 were executed by the Spanish Inquisition. That's right - people who claim that four times as many people as live in all of 21st century Spain were executed in Southern Spain in the 1500s.
The fact is that in the XVIth century the Dutch were engaged in a civil war against the Spanish throne. I'm sure that something like 50,000 people died over the course of this conflict. But separating purely religiously motivated executions from political assassinations and executions for treason is pretty much impossible. There was a Calvinist army fighting Catholic troops - every encounter would have some religious aspect to it.
If Fiske is going to chalk up the deaths of Protestants in Holland to pure religious bigotry, then he'll have to add all the Irish and Northern Scottish deaths and land clearances to England's and Protestantism's balance sheet. But he's already ruled that out - since he feels that the tender mercies of Cromwell in Ireland can't be compared to the brutality of the Spanish Throne in Holland.
From little that I know, I understand that Albigenses were rather extreme in their beliefs. I also understand that, when looking back this many centuries, one has to view that world through the standards of that time. Yet, I do not find it normal to write about a mass slaughter matter-of-factly. The human sacrifice of the Incas was not up to our standards of civility, and yet I cannot imagine that someone would write today, "They have been finally wiped out by ..." And if someone did, I would consider that an abomination.
As for the insane people who claim that millions and millions were killed by inquisition, thank you for letting me know; this is new for me; the claim is clearly ridiculous. However, Fiske is one of the majot historians of the XIX century, he knows the difference between "slaughtered for herecy" and "killed in fighting." I suspect that you have read something by him, and can attest yourself that, while his interpretations may be in question, his motivations are not.
I certainly hope that you do not question my motivations either: it is not my intention to show the Church in a bad light (in fact, I wish it was more proactive in claiming its rightful place in history of Europe, as Pope only recently asserted). Yet, the ending of the article on Albigenses did leave a bad feeling in my mouth. Despite your very informative reply, which I read with great interest, that feeling has not dissipated, I am sorry to say.