Conceding should only be available during your turn

Shows what kind of Pokemon trainer you would be...

In what possible way would conceding a card game constitute some kind of animal abuse? You watch too much anime. Pokémon aren't real. And how many do you have rotting in your PC boxes? Or do you take each of them out every day for socialisation, food and exercise?

It's a card game. And in this case, a digital one at that. No living thing is actually hurt whatever we do. Your ego seems to be the only thing wounded by concessions.

"My opponent didn't let me win the way I wanted." The only thing worse than a sore loser is a sore winner.

You are not going to win every game. Even the best players will never attain a 100% winrate. Card games have too much variance. We all get a little tilted and frustrated from time to time. We're only human. But as much as possible, we should try to take both wins and losses graciously, and learn as much as we can from each to improve for the next match.

Wins are hard won, especially in more competitive environments. And there is nothing more frustrating than being stuck in a game you cannot win. Not to mention the fact that it is wasting both players time. It is far better to allow the losing player to concede at any time, at their discretion, and move on to the next match.

The winner gets the win they deserve and both players are free to prepare for and play more games.

The alternative scenario where players are not allowed to concede would only make things worse. You are trapping both players in an uncomfortable situation where one or both of them simply wish to be done with the game, but they are both forced to keep playing. And if the losing player does get angry, forcing them to sit there losing isn't going to improve matters.

Again. Just take the W.

Who can say? It's harder to discern tone and intent from text.

Either way, people do make points like that in earnest, and I stand by everything I said.