How many Presbyterians fly planes into buildings? How many Hindus blow themselves up to kill innocent people?

The point of Tim McVeigh and Ted Kaczynski is that certain people will commit these acts regardless of the reasons. A person who wants to kill and terrorize will find something to justify it. The terrorists on 9/11 wanted to terrorize and they used Islam as justification. If there was no Islam, they would have picked something else to justify it.