Make Ranks Meaningful
As the title says; make ranks meaningful and more than just a bragging right, a flimsy and often faulty matchmaking tool, and an indicator of how well a player plays by your "rules" of how you think the games should be played (the reward system/pip system).
It is an incredibly simple fix, really, that encourages players to play by your "rules" and try to get and maintain as high of a rank as they can manage:
Brown Tier - No change.
Yellow Tier - 25% post-game bonus to all bloodpoints.
Green Tier - 50% post-game bonus.
Purple Tier - 75% post-game bonus.
Red Tier - 85% at Rank 4; 90% at Rank 3; 95% at Rank 2; 100% at Rank 1
The bonus bloodpoints alone would be worth it for many players to actually try to push as high as they can get and work more actively towards your reward/pip system goals. Adjust the values if you need to - but I think the same 25-point increments used by several perks would be just fine (with adjustment at Red ranks since they are difficult to maintain and progress through)
Otherwise, you'll have players (like me) that see how pointless ranks are and ignore your pip system and emblem requirements and just play the game - whether we play laid-back one match or decide to get salty when we get worked up in another.
Literally the only reason not to implement this change is because you would be admitting that despite your claims - you want the game to continue being as grindy as you can get away with; and this would "speed up" the grind for players even though it would require them actually playing the way you keep trying to force players to play.