Downvotes are neither bad nor a personal attack. The top answer to Could we please be a bit nicer to the n00bs? put it best:
- The up/down vote system is not just about rep, it is the quality control mechanism for Stack Overflow.
... the up/down vote system is the core of how we get the "good stuff" up and the "bad stuff" down. It is not designed to be a personal attack against the users in question.
Users must have 125 rep to downvote, and the reputation privilege is described to be cast on questions and answers that "are least useful... egregiously sloppy, no-effort-expended post, or an answer that is clearly and perhaps dangerously incorrect," but, really, they're used for whatever we want. Other motivators are listed in Why do you cast downvotes on answers?
Whatever the reason, don't take it personally. Similar to your behaviour in a discussion, it makes no sense to get upset when someone disagrees with, finds a flaw in, or offers an alternative to your argument.* This is something we all learn growing up socially. Those that don't abide are communally pegged as immature idiots, even if they were right.
Voting is anonymous, meant to encourage more votes, especially downvotes with it's emotional blast radius. Shog9♦, in an answer to Feature request: @Downvoter sends a notification to all downvoters for your post, defends downvote anonymity, why we should STFU about votes/rep, and how to better ask for suggestions:
I've thought more about this, and frankly... I don't like the idea of
leaving a comment for down-voters at all, with or without
notification. Down-voting isn't supposed to open a dialog - new users
are encouraged to comment when
down-voting,
but it's not mandatory - and if they don't feel the need, that's just
fine.
Furthermore, I've seen too many instances where a "Why the downvote?"
comment poisons further discussion, turning comments into a debate
over whether the vote was merited - this is noise, as comments are
supposed to be relevant to the content of the post itself. In most
cases - and especially when comments have already been posted prior to
the request - I flag or delete these downvoter-addressed
comments.
It's easy to feel frustrated, when you put substantial effort into a
post only to see it down-voted without explanation. But this is an
attitude that must be discouraged rather than justified. Remember:
voting is primarily a means of communicating with other readers and
with the system itself; comments should be reserved for providing
auxiliary information, suggestions, and constructive criticism to the
author. They're two separate mediums, and need to stay that way.
Now, if you notice your post being down-voted and honestly want advice
on improving it - regardless of whether or not that advice comes from
the same users who down-voted it - by all means, ask for suggestions!
Just stay focused on the content, not the voting or other users:
Good
Can anyone suggest improvements or corrections to this?
Bad
@Downvoter, please leave a comment. Rawr!
Stupid anonymous down-voting cowards!
Why the downvotes???
TL;DR
Downvoting is required to bury bad questions and answers and reveal good ones, but receiving a downvote doesn't necessarily mean anything. Other people vote for different reasons, and a few votes here and there don't matter, so don't sweat it.
*It makes sense when this discussion has real consequences, like getting or not getting the new Transformers toy with your Happy Meal, but that's besides the point.)