Q:

Was Classic Mayan civilization really so gruesome?

(I don't really know how to ask this question, so help in editing it to better fit the StackExchange format would be quite welcome.)
From what I can tell, Classical Mayan civilization was exceptionally gruesome.  So much so, that I have a hard time accepting it.  Reading articles on Wikipedia, this is what I see: the cities were almost constantly at war with each other, war captives were often sacrificed, kings and nobles would frequently pierce their bodies for blood in public ceremonies (in horrifying ways involving thorns, ropes, and delicate body parts), there were sacrifices of children, and I've heard there are a few examples of cannibalism.
Can that be right?  Can Mayan civilization really have been so horrifying?
I know very little about the period, and I'm hoping these aspects of it didn't really exist.

A:

Their civilization did in fact engage in all those things. If anything, its been underplayed.
One important thing to note here is that things appeared to get particularly bloody (at least in terms of the inter-city warfare) towards the end when their Civilization was collapsing. Jared Diamond goes over this in his book Collapse, which has a whole chapter dealing with the Maya. 
They had horrible erosion problems, and food and freshwater storage issues due to their climate and terrain. This left them incredibly vulnerable to droughts. Droughts of course happened periodically, but it appears that a particularly long one (along with soil erosion issues) may be what finally took them out. 
Anyway, whenever a drought happened, once they went through the stores, there were just not enough resources to go around. In a densely populated farming society that meant that one way or another, lots of people were gonna die. Its tough to blame desperate people for preferring it to be the folks in the next town over rather than themselves via starvation.

A:

All of these things happened, and worse.  You did not mention the flaying of living people, the drugging of participants, and more.
But, it is unfair to ascribe this only to the Maya.  They, like other non-Aztec cultures in Mesoamerica, performed these practices less than the Aztecs[1].  
The Aztec orchestrated this kind of imperialistic ritual (in hopes of advancing the practices of the semi-mythical Toltecs).  
The question could be changed in order to not perjure the Maya in-absentia of their context.
[1] Bancroft, Hubert Howe (1882). The Native Races, Volume 2, Civilized Nations. p704

