Quest for Purity

In the book The Looming Tower, Lawrence Wright talks about the Taliban and how they had no real interest in governing but they only had a quest for purity that overtakes everything. I thought about this quest for purity and then I heard about an instance at a library where a patron became incensed that some objectionable book about gay couples came up in a search for an American president. The first and last names of the president were in the record separately of the objectionable book as authors. This patron did not want to have to even see the title of this book in her search and the library should do something about this. This seems like the quest for purity as well.
I've been guilty of this as well, especially in protecting my child from the world. But as adults, how much can we expect the world to shift around so that we can see only purity and innocence. I once told someone in my family that a book I was reading was disturbing and she said, "I don't like to be disturbed." This in turn disturbed me as I don't feel that way anymore. I figure no matter how horrendous the situation in the book, or on the news is, if the person/s going through it can survive it, I can deal with just hearing about it.
Anyway, instead of the quest for purity that the extremists of any religion strives for, it's the quest for truth that I value. But I do realize that diving headlong into the addictive pursuits is a distraction at best from the real quest.