Agreed.
We're all volunteers here, and no one's getting paid to answer questions with a smile.
While I try not to be too snarky with my answers, I definitely don't sugar coat them. You ask a question, you get a straightforward answer. If you want "pretty please" and "thank you" and "have a wonderful, bright day," I'm not your man... but if you want to know why your Airport Extreme isn't working, I'll tell you why in no uncertain terms (without being rude).
Sometimes snarkiness is used as a learning tool -- I tend to use a lot of metaphors in my answers, which I believe helps non-technical people relate their computer questions to events and circumstances they may understand from other areas of life, such as:
1) "I don't have my OS X install CDs anymore..." gets answered with "You wouldn't lose the keys to your car, why lose the keys (CDs) to your computer?"
2) "My computer won't work. What's wrong with it?" gets answered with "If you called a mechanic on the phone and said, 'My car won't work... what exactly is wrong with it and how much will it cost to fix it?' you'd either get dead silence on the other end, or a mechanic that explains unkindly that you haven't given NEARLY enough information to even warrant a response."
Hopefully those things educate the poster into realizing that we're not mind-readers and that they should think through their questions before posting them (after all, we think through our answers before answering... for the most part!). No one's going to do anything for anyone else, here or anywhere else in life... it is up to you to be clear, concise, and specific about what you want, and that's something that should not have to be taught to people. I'll typically gloss over or give a one-liner to questions posed that:
1) Are written with horrible grammar and/or spelling. Not everyone is a literary genius, but if your post is sixteen lines long, all in one paragraph, all lowercase, missing periods, commas, and appropriate grammatical marks, and simply runs on and on, well... explain your problem to someone else and have THEM type it for you. Unless you can communicate your problem to us, we cannot help. I won't make you feel bad about having poor grammar skills, but you should fully realize your capabilities and take the appropriate steps in order to construct a readable query. Hey, I can't understand the terminology of the stock market all that well, so I'll be the first to admit it, I won't pretend to know it, and I'll certainly seek help from someone more knowledgeable than I if I needed to communicate to someone about it. I'm old school: learn proper grammar and spelling. It's harder for some people than others, but that's life. I had a hell of a time with statistics while others breezed through it. Boo hoo.
2) Have spam links in the query... like Cheryl said, forums are spam-bait where spammers come to push their links and increase their Google scores. We get a lot of that. If you sound like a spammer (posting unrelated ideas into a thread, or including links to web design companies, off-shore cell phone businesses, etc.), more than likely you'll get crickets chirping or a firm slap on the wrist, and, in my case, I'll deduct from your reputation as well.
3) Ramble on and on... it's always better to give too much information than too little, but sometimes, and this goes hand-in-hand with point (1) here, people go overboard. State your problem, give the information clearly, and await an answer. I'm all about efficiency. I don't know you, I don't care to know you (unless you're in my city, otherwise our paths will never cross), and the whole point of this place is to answer questions, not make lifelong friends/penpals. Save the life story for your cocktail party at the end of the week -- we're here to get down to business, not talk about your 17-year-old drugged-out son and how he deleted your crappy collection of recipes in Word.
Just my buck-o-nine (thought that was a little more than $0.02).