Weeding out the officers that would commit infractions that result in civil suits will probably also weed out those that would actual commit a more serious crime.
If one of the 18 use of force complaints against Chauvin had also resulted in a civil lawsuit that found Chauvin liable, he might have been removed from the force earlier.
That's one theory at least—I think it's a reasonable one.
I don't think removing QI from police officers should be the end-state of reform, but I think it's a necessary step and a good one.