its probably so that they can deport you back without any difficulty for lying if at some point they do find you do harbor those intentions but can't prove unequivocally that you are involved in a terrorist plot or if you haven't carried one out yet. If they can just get info on you that you do harbor any of these feeling they can deport you immediately on the pretenses of lying on your visa application. One less person to worry about or dedicate resources to monitoring.No seriously, if you apply for a European or American visa from here those really are the type of questions that they ask (I saw them when one of my relatives wanted to go visit the UK a few months back).
I'm begging to ask them though.......why would a real terrorist say that he's one on the visa questionnaire?!?!? oO