The main focus of Arqade isn't to help people. It sounds wrong, because what else do we do here? We're actually kinda like GameFAQs, except with a much narrower focus. We are here to build a repository of knowledge. The ideal is, "Write once, read many". That's why people write FAQs on GameFAQs; to help those that read it. They don't write a new FAQ for every person; it's written once, and read many times by lots of people. Similarly, that's exactly what we do here. Does it help people? Yes. But it happens as a natural byproduct of what we do here. It's not the focus.
We're here to ensure that what goes into that repository is high quality, and makes the Internet better just by existing. We get a lot of users who don't bother reading what we're about. They assume we're a forum, or something like Reddit, and just go nuts. Their reception tends to be a bit grating, because they don't understand what we're about. And we continue to work with those that are willing to learn, so they become better members here.
But back to downvotes: their purpose is to signal what content is good or bad. That's the primary focus. That comes above helping users, every single time. If a user is feeling charitable, they can (and quite often, will) leave a comment about what's wrong, and what needs fixing. I know I do that on a regular basis. That's part of our new user experience, which is a continual work in progress. But that's optional. That's why comments are not required when downvoting.
Our main focus is the quality of our content. If a user continually contributes low quality, it doesn't matter whether they need help or not. They can (and have been) suspended for treating Arqade as a dumping ground of poorly thought out or written questions. We don't mind helping users, but we do expect (and enforce) a level of standard that's much higher than elsewhere on the Internet. And I, for one, like it that way.