The system as it stands basically is just a means of making PvP less fun for everyone.
The only people this system works for is people who RPK while blue & count their MC & do deliveries to farm rep. This is the playstyle that this system encourages; mechanically, that is what the game is practically telling you to do. Basically, a criminal that just exploits broken mechanics to get the best of both worlds at the expense of having to wait out MC occasionally(which you can just log off or play an alt for... terrible design), and having to fit deliveries into their schedule. The thing is, I have a hard time saying this is a fun playstyle, either, even though it's the 'best of both worlds' situation and the functional 'meta'. Really, it's pretty tedious as it turns PvP into a one-sided affair, and frankly creates a tedious gameplay loop of boring PvE delivery quests & literally not playing your character while waiting for MC to expire.
I'm not an RPK, and I can say that the current MC/rep/flag system has only served to make my experience with the PvP in MO2 worse. I don't think there is ever going to be meaningful PvP for someone with my playstyle in MO2 with this system. That's bad enough, but it does nothing to actually curtail grief, as the current meta just involves griefing within the confines of an extremely tedious MC/rep system with no consequence, or going outlaw and disregarding said consequences entirely.
Frankly, it sucks for people who want to do the outlaw playstyle, and it sucks for people who want to do the lawful playstyle. The only people this system is 'good' for is people who exploit it for murder without consequence, which is most of the playerbase (which makes sense since this is the meta it creates mechanically, and people will always aim to do what is most efficient within the rule-set), but it still makes the game less fun/more tedious even for them.
Basically, the functional reality of these mechanics are the opposite of what the system is trying to accomplish. They should either scrap it entirely for something easier to implement like MO1 had, or rework it so that it does serve the purpose of delineating criminal from lawful, and preferably also makes the criminal gameplay loop less tedious. Either of these changes would actually allow for fun PvP, since in one instance it is an actual 'wild west' situation and everyone knows what they are getting into, while in the other there is at least an obvious indicator of who is allowed to kill whom.
As it stands now, it meets neither the objective of being 'impartial but brutal' like MO1, nor of the aimed objective of 'delineating criminal from lawful'. Instead it creates a system where the most heinous criminals are typically blues working within the confines of a poorly implemented PK system, while any other playstyle gets the shaft.
The result is the system just feels willfully unjust. This is how you get people to just sit around in cities and never want to go outside; why would I want to go out into the world when I know the mechanics behind PKing are so broken? I have to either accept a MC for attacking first, or else I am always at the mercy of the local blue bandits...?