https://www.chess.com/game/live/120336613441?username=johnnyerasmic
This game?
No mate, you beat him 100% fair and square. Part of the fun in games like this is to promote to queens and ladder mate, cos it's actually one of the easiest ways of checkmating your opponent without cornering yourself and potentially stalemating. Checkmate is, after all, the aim of hte game.
The person complaining is just a, em, well, complainer. Instead of complaining, he should really be studying the game to figure out why he lost ¯\_(ツ)_/¯ Question he should be asking is why he allowed you to promote two queens, not why you did.
If you wanted to get really technical; he's right, you could've mated him with just the one queen. Answer to that: so? You had a pawn that you could utilise, so you utilised it. Congrats! He was possibly trying to bate you into stalemate which is actually quite easy to do in this situation.
Well done on the win, looks like it was quite a long game.
A recent opponent expressed irritation towards the end of our game. I had a rook and 3 pawns, he had a knight and a pawn. The simplest way (it seemed to me) was to promote my pawns, thereby giving me 2 x queens and getting a 'ladder' checkmate. He described this as 'a slap in the face' pointing out that I could have got a checkmate without the extra piece. The thing is, I was getting a bit short on time, and I'd been tilting all day and so I decided to go for the simplest win, without risking a blunder/stalemate. It never occurred to me that my play was unsporting - I just wanted the win. Does he have a point? Or is this sour grapes at losing?