Pain?
If you're playing at this for the rep, you're doing it wrong.
Rep is just a rough measure of how much the community trusts you.
Losing rep isn't a "punishment". Think of it as a sort of "poke" to improve your answer. There shouldn't be much pain in losing rep.
Why downvote?
A downvote(answer) can mean:
- This is an inefficient way of doing it
- This is wrong
- This does not follow our guidelines
- This does not answer the question
- I hate you/I want my answer to be ranked higher than yours{*}
Question downvotes usually mean "bad question", and are free to use.
Should downvoters be penalised more?
The people downvoting answers are just taking part in a community process of selecting great answers. They're helping the community, so there really shouldn't be a penalty for them. Of course, the penalty is there to just make sure they don't overuse/abuse the ability--since it penalizes the downvoted user as well. It shouldn't be an "eye for an eye", the downvoters aren't doing anything bad from the point of view of the community.
Regarding that answer
- Even if it helped the OP, other community members must have downvoted it. I don't think the OP himself downvoted it.
- "It helped the OP" does not mean that it's a good answer. Especially a "just a link" answer. We prefer answers that explain the situation clearly.
*"I hate you", if done too often, is automagically reversed. "I want my answer to get ranked higher" is drowned out by votes from the rest of the community, if it's a good answer. So not much of an issue.