There is all sorts of gold in this somethingawful forum thread on the Fate-verse (via @monoids). I particularly like the directly linked entry (which made me break out in helpless laughter):

The Fate franchise is like Paris. It seems pretty and fun, and then you dig a little and the whole thing is built on a giant sprawling maze of dead people.

Then another golden quote:

[Fate] Mages might not all be psychopaths but I can say without reservation that they are all assholes.

Except for Waver, but then again he's living in the house of two old people he brainwashed into thinking they're his grandparents.

I think Waver gets better over Fate/Zero but yes, this. It is not a coincidence that the Fate-verse related works that I like best are the ones that have the least to do with the main story and the serious characters.

(The Fate-verse is the usual term for the setting of Fate/Stay Night, Fate/Zero, sort of Kara no Kyoukai and Tsukihime, and various other works that haven't been animated yet. Fate/Kaleid Liner Prisma Illya makes light-hearted references to it, which is really the best way; you get the cool awesome bits without having to think about the pools of blood.)