Don't Resign Once You Lose a Piece

I've played a lot of games where my opponent would blunder away a piece and immediately resign.  This game that I played, (which I didn't play particularly well), is a decent example of why a resignation should only be declared when there's no opportunity to win or draw.  If you're a GM, I get it.  But otherwise, I believe it's best to keep going.  In this game, which I played on another site, I lose a piece after 11 moves and by move 27 my opponent and I agree to a draw.  I had White pieces.