Why do I get zero xp for playing out a lost game in normals?

I get that it's probably to limit the amount of xp you get from challenging your friend and surrender boosting but I should at least get SOMETHING to level up my vault. Especially if I play a game out to round 7+ and end up losing. I'm not complaining, I really like the game but can someone explain to me why this is the case? can riot not tell that I am playing a normal game with a random stranger and there is no text chat to even coordinate a surrender boost?

Like the biggest thing stopping me from grinding this game is the fact how I barely have any champions so if I just dick around with some half finished deck trying to level up my vault to 10 so I can get an expedition token or if I am trying to level up my region and play a 30 minute game and lose I get zero xp it literally gives someone zero incentive to play a game out instead of being like "oh I got a bad hand" or "yeah there is no way I can win this" making someone surrender.

Does this make any sense? I'm not trying to flame or complain im just wondering