I think there's a few factors at work:
1) The programmer was there once, and probably worked through it on their own. Nobody held their hand.
2) The information being asked is probably in every programming book every written and duplicated hundreds of thousands of times on the internet.
3) Dealing with past programmer-hopefuls has been really disappointing as most of them never get anywhere.
Helping people learn is -awesome-. Holding their hand and doing everything for them is horrifyingly boring and frustrating.
At work, I've had people who were genuinely interested in working hard and learning. They were great and I don't regret a second of the time I spent. These people were generally inclined to look things up for themselves, and only ask for help when they get stuck.
I've had others that I gave way more time than the good learners and they were going nowhere. Then management stepped in and told me I didn't give them enough time and demanded that I spend 1-2 hours every day with them. After weeks of losing 5-10 hours a week, I finally managed to get management to see that no amount of time would help. These people were generally inclined to wait until they could ask a question, instead of looking it up for themselves. It often meant days of non-productivity since they get lost again as soon as you leave their desk.
So to conclude, when a novice programmer asks a really naive question, the first response is to assume they haven't done any legwork on their own, and so the question is really annoying.