Resetting a mob so another group has more time to get there, while you may be intending to do good by the group that's not there yet, you are harming those that were already fighting.
Then, by your logic, people who do resets are also choosing to potentially harm themselves in hopes of benefiting the greater good.

See, it's not so black and white... which is why SE is emphasizing intent above all else, as they should.

A good reset easily results in more people being helped than being harmed. There's no denying this. In addition, people who are playing the content as intended and grouped into parties are almost always likely to still get full credit if they're already there. I run hunts all the time; I know this first-hand.