People have the privilege if deleting in order to be able to remove posts that ***need*** to be deleted. This is a quasi-moderation privilege so treat it with the same respect we do. 

If we're talking about questions, the close system should be used first. This allows a poster to revise and reopen their question. And closing it without answers or positive score will see it [automatically deleted][1]. Duplicates feed into a SEO system which deleting can hurt.

If we're looking at answers, there's a bit more to do here in that it's far more common there's a "non-answer" posted in the answer section than a question asked that needs to be urgently deleted.

Save your votes for things that cause harm.  
Leave the "does no good" for the system.


  [1]: https://meta.stackexchange.com/questions/78048/enable-automatic-deletion-of-old-unanswered-zero-score-questions-after-a-year