Everyone has the right to down-vote whatever they want with their stake. It's all part of the 7-day process to reach consensus around the "value" of a post.

Personally, I don't use downvotes except in cases of scammers, spam, when JSun took over, etc.

But I don't have a problem when others downvote my content, except when it becomes systematic.

That payout wasn't "mine" yet. (Big lesson about Steem/Hive there) Until voting is over and the payout happens, nobody has received anything, and nothing can be stolen.

Think of it as a practice in non-attachment.