Not resigning etiquette

I think a better question is, why on earth would you want to do this? Is your own time really so worthless? Surely at the very least you'd rather just end the game and get back to playing real chess?

I think the only valid complaint about somebody not resigning is that it is wasting your time. But you clearly don't value your time anyway, if you'd rather do this, so why do you care if your opponent resigns or not?

@Snuffington that's a good question.

I agree that when your opponent is not resigning, tends to be boring thus you may feel you are wasting your time.

However, when I get many queens it can get hard avoiding stalemate. Which I need to practice because under time pressure I have difficulties avoiding stalemates. Or I underpromote a little bit more challenging. For instance when I have increment I have tried underpromoting to 2 bishops. Also there are interesting mates when your opponent has pawns and a king etc..

So, you get to be creative each time.

Continuing to play on is a player's right. In any case, playing on when only, say, a piece down can lead to a win. And playing on with only a king can lead to a draw.

Personally, what I don't like is when an opponent in a losing position neither plays on nor resigns, but just lets the clock run down.

Better to just checkmate your opponent and move on. If you try to promote a bunch of pawns to "rub it in" you will inevitably make a mistake and give someone a stalemate, encouraging his behavior.