Like I wrote in my comment:

@Hendriks3D while I sure understand the frustration of not getting an answer accepted (where the OP comments saying how you helped them), down voting the question out of spite is just not right.

That kind of voting is wrong, period.

On the DV Privilege page is says when to down vote:

###When should I vote down?

Use your downvotes whenever you encounter an egregiously sloppy, no-effort-expended post, or an answer that is clearly and perhaps dangerously incorrect.

Nowhere in there (or anywhere else will you find) "Down vote whenever you are unhappy with the OP."

Aside from the very big problem with that type of behavior, there is an underlying issue, which is: voting on anything other then the content of the post.

Anytime you cast a vote (Up, Down, Close, or Delete) you should be voting only on the content. Whenever other things start to creep in, problems start. Then you have unhappy users, next it is you holding a grudge, then the other guy which you did not UV is angry and on and on it goes.

"He already has enough rep, no point UVing that question."
"I'm not UVing that - it will push his answer above mine."
"I know this guy, he was a jerk in second grade." DVed.

Do not vote on anything like this is a popularity contest, just vote on the content.

Would be an interesting experiment, anonymize the posts then see if people vote differently.
In a perfect world all the votes would be the same, but as we all know nothing's perfect. Like the example that spurred this question, people do not vote with pure intentions.

All that only goes for the main site, on meta it is a bit different.
Here in cases where somebody has a proposal or feature request, voting is more of a "agree, disagree" than "good post, bad post". If for example (and by saying this I'm begging for it to be done) my answer here gets DVed, I wont take it as if I wrote a bad answer, but rather that there is some user that wants to keep voting on whatever whims they have.

Like I wrote in my comment:

@Hendriks3D while I sure understand the frustration of not getting an answer accepted (where the OP comments saying how you helped them), down voting the question out of spite is just not right.

That kind of voting is wrong, period.

On the DV Privilege page is says when to down vote:

When should I vote down?

Use your downvotes whenever you encounter an egregiously sloppy, no-effort-expended post, or an answer that is clearly and perhaps dangerously incorrect.

Nowhere in there (or anywhere else will you find) "Down vote whenever you are unhappy with the OP."

Aside from the very big problem with that type of behavior, there is an underlying issue, which is: voting on anything other then the content of the post.

Anytime you cast a vote (Up, Down, Close, or Delete) you should be voting only on the content. Whenever other things start to creep in, problems start. Then you have unhappy users, next it is you holding a grudge, then the other guy which you did not UV is angry and on and on it goes.

"He already has enough rep, no point UVing that question."
"I'm not UVing that - it will push his answer above mine."
"I know this guy, he was a jerk in second grade." DVed.

Do not vote on anything like this is a popularity contest, just vote on the content.

Would be an interesting experiment, anonymize the posts then see if people vote differently.
In a perfect world all the votes would be the same, but as we all know nothing's perfect. Like the example that spurred this question, people do not vote with pure intentions.

All that only goes for the main site, on meta it is a bit different.
Here in cases where somebody has a proposal or feature request, voting is more of a "agree, disagree" than "good post, bad post". If for example (and by saying this I'm begging for it to be done) my answer here gets DVed, I wont take it as if I wrote a bad answer, but rather that there is some user that wants to keep voting on whatever whims they have.