You are absolutely correct ... BUT ... you neglected to say this should apply to BOTH sides!!

The defender is also fighting in the arena: "He should win. Otherwise he is loser."

I also agree with przeeeeeemo: battle timers suck. However, at this moment, I have a classic arena battle (on auto) that has be going on (so far) for 19 minutes, 12 seconds and shows no sign of ending any time soon.  I have to leave for work soon. If I leave it going (on auto) while I'm at work, what do you suggest if it is still making no progress when I get back about 9 hours later? Concede? Why should I concede, rather than the defender? Or perhaps I should leave it going and never again do anything in the game?

After some (un)reasonable time (10 minutes?) the battle should end as a draw -- no reward, no lose of token.

I agree with Hex. Three times today I have come to a draw and I am the one that has to lose a token, not right. To get anywere in this game you have to pay so draws should not require you to lose your token. This is frustrating to the point I should just quit and play my console games. one time fee for game and done. The Idea behind this game started out to be cool but there are a lot of issues when it comes to the integrity of the developers. Yes, I know it's a bussiness but there should be some integrity as well. So, Bye Bye Plarium. I doubt you will be around very long based on your bussiness model.

That's a pretty funny reason to quit... there are plenty of good reasons to quit but 'I don't get a win when I don't manage to beat a team' isn't exactly among them. 

If you just leave it running, you'll get an error after like half an hour or 45 minutes, the famous 1000 turn limit that's causing some people to fail certain Doom Tower fights. 

When you attack a team in the arena, you have two major advantages as the attacker, being able to see all the champions in the defending team and adjusting your team accordingly, plus being able to manually control your champions. The defending team just has to fight against anyone who chooses to attack it, on auto. It's only fair that at least they get the win against attacking teams which are unable to defeat them. 

+1 on this

Defense is at such a disadvantage, and should win a stalemate

The worst thing to surrender is when I'm level 50 and the other party is level 60. , and the fight has gone to the limit of 1500 rounds. It's unfair if I have to lose. Should share points or no one wins.

holy necro. 

account level doesn't really matter and isn't always a good prediction of account strength in arena when below say, 80-90. one can get their account level up just by grinding campaign which doesn't necessarily mean they're building champs well in a pvp setting. 

if it's in classic or tag there's not a great argument because their defense and choices are static/fixed while you have the freedom to make more choiced in the fight.