It became all the more clear that Rick isn’t necessarily capable of letting his mercy prevail over his wrath, because it isn’t just his own wrath that he’s aiming to squash.
In some ways, he continues bringing the fight to the Saviors as a way to provide justice for everyone who’s lost loved ones to the dreaded villains.
Not that it works very often, but that particular sense of dedication is perhaps a telling sign that Rick can never be the person to usher in harmonious outcomes.
More to the point, Rick made it clear in “Do Not Lead Us Astray” that he attempted his botched assassination attempt on Negan as a favor to Maggie, who was truly grateful for his efforts.