Shouldn't MMR be tied to the objective?

Im genuinely confused here, so tell me what you think. I think MMR should work like this:

Let's assume that if you are at the right MMR and play against 3 other teams, you will extract with the bounty 1 out of 4 times on average. If you play duos then 1 out of 6. Why can't we have a system where you gain a certain ammount of rating with bounty extracted and lose 1/4 or 1/6 of that ammount if you dont extract with the bounty.

What could motivate people to play the objective if not a system that... idk, rewards you to play the objective? Right now I don't see much incentive for going for the boutny. You get a huge ammount of XP from a boon that costs 1 point (thats like few specials and a couple of baloons) You can literally just loot dead bodies with vulture and witness and extract empty-handed and there is literally nothing to lose with a playstyle like this.

Now this wouldn't really be a problem if the events weren't as long/longer than the periods between them.

I can't even blame players that play this way, when the game just rewards you for XP farming. I really feel like lately the games are really boring. 50% of the time when i banish the boss, noone is even around to challenge me/us and the extracts are usually right next to the boss lair. Why cant we just have a system that sorts players into groups that have similar playstyle, so that everyone can have a good time? The current MMR system clearly doesn't do anything for the game.

Maybe i'm the problem and the game just isn't meant for a player like me, i don't know. What do you think?