Hearthpwn

I'm coming back to play after a couple year break, so nearly all the current cards are very new to me. That means a lot of losses as I go through the process of learning & rebuilding my collection. 

I remember people sometimes refusing to kill you, but it seems to be more common now. It's always been really annoying to me. I've already played a few games today where I'm down to health of just 1 or 2, with no cards in play. But despite having a full board of high attack cards or spells, they continuously refuse to win. 

I hate conceding, though I assume that a concede is the same value as a direct win. 

Is there a benefit to the player who does this? Is it just a way to be annoying?