I should have said "silly, petty and a waste of time FOR ME". Apologies to those who took it personally.
For me, it depends on many factors.
- What is my opponent's rating?
- What are the stakes in resigning (eg in a tournament etc)?
- Do I have any potential comeback if I continue on (eg loss of a piece with compensation, no matter the size of the compensation)?
- What is my mood for the day?
if I play 30m and my opponent still blunder a winning position, I take it because it's their fault for not taking such a long time to see a better move. but in most of the cases maybe I'm the same as yours (resigning after down a piece for 5 moves) so its ok to feel that way, it just depends on the position where if you feel you still have a chance to exploit opponents' weaknesses (like some back rank problems or a loose piece on opponents' side), I think you should try rather than resigning even in longer time controls.