Moral

When you are loosing a game, is it Amoral to win it on time?

No. Time control exists to add a new dimension to the game.

@shoopRLB But sometimes your Opponent has 5 Queens and you just 2 pawns.

there are many ways to win a game that don't involve sound strategy, amoral no, but it wont always work and leads to bad habits in general

you can play longer time controls if you want less wins/losses on time.

If your opponent squandered his clock promoting 5 queens, instead of checkmating you, it is perfectly appropriate for him to lose on time :/.

@mjqxxxx when you dont habe time almost every Player is wanting more Queens!

You are not loosing if you win on time ;) Truly.
You can only assess a position and say, that with "correct" play, one side should win.

You loose having even 8 queens more, if I checkmate you.
So your winning chances cannot be reduced to simple material count.

You could also say: we leave checkmate out of the game, cause its amoral you can checkmate me, if I already have won your two bishops. So as soon as one side has +6 more in material count, we just finish the game.

You always have to take into consideration "all variables" you both agreed to (usually the common chess rules + time control + maybe some tournament/otb rules).
And if "time" is one of the variables you both added to the game, then you both have to deal with it.
Otherwise it makes no sense to add it at all.

It maybe feels really bad to loose on time, cause you might think "just because of time".
But hey, "just because I have overseen some mate-in-one" does not feel better.
In the end you lost, because you did not play "correctly".

@brainwind so let say us that time is a very important Dimension in our "time".