From what I can see, the design of POTD kicks the person out if there are no living members within the dungeon. I believe this means that if a party were to d/c at the same time they two would be kicked out and thus have a KO on their record.

Now the reason why this is so important is because Solo players have a lot going against them in any attempt at reaching floor 200. One can spend 5hrs reaching 100 or even 120 only to d/c and lose all their progress.

With that in mind, why not allow solo runs to progress to 200 even if they have KOs? Just have those KO's be part of the score rather than penalizing said player from attempting to continue that run to 200.

Now if SE could guarantee the protection of a players run when they d/c that would be another story but I do believe because of the design of POTD it's not possible which is why I think the next solution is to remove KO from affecting a solo player's attempt at 200.