Board Game Arena

Why is there an ELO penalty for the winner when the opponent abandons? I had a player abandon a game today in Terraforming Mars because I was clearly winning and he did not want to wait to the concede point. The concede point may in fact be at 60-80% of the game time even if metrics say 50%.

There are other ways to detect win trading this way seems to punish a player for getting lucky.