I can see that you've received some down votes, and your question here is probably rooted more in your reaction to receiving these than anything. I think part of your frustration is that your answer was DV'd because it was a question in the answer section.
This DV was because you were using the SE site incorrectly. See the help section: https://unix.stackexchange.com/tour.
The SE sites are strongly structured in their model of Q&A with voting + comments. This is just how this particular site works and it's best to just adapt to it, if you want to participate within this community.
There are other forums that do things differently, but this particular site is structured like this because Joel Spolsky and Jeff Atwood were trying to achieve something new on the Internet by providing a place for others to participate in a manner where experts could earn reputation through their efforts.
The natural approach, IMO, is that if you provide users a method for earning something, means that you have to provide a method for taking that rep away, hence the voting structure.
When people vote either way, they can leave a comment explaining why they did so or not, but they are not obligated to do so. When someone DV's a answer, they are losing a portion of their rep (-1) when they do it so they typically must feel strongly to do so, to forgo some of their rep.