I don’t agree at all. Ideally laws are enforced every time. We shouldn’t be happy that only some murderers are caught. I can’t see how it’s good that laws are enforced essentially at random. That does all kinds of bad things. It covers up racism by giving police a plausible excuse. It allows us to hide how draconian our laws are by only inflicting their punishment on a few people. It allows us to keep laws on the books that people actually don’t broadly agree with (and thus shouldn’t be laws in a democracy).
Enforcement should be compassionate by design, not faux-compassionate by mistake.
I don’t feel like my civil liberties are infringed on when the government unexpectedly inspects a meat packing plant to check for listeria. It communicates that the plant had better be on top of the listeria thing all the time because you never know when you might be tested. When they are used to target racial minorities, they basically communicate to the racial minorities the same thing: you better not be black, because you never know when we might check.
Trying to get people to be mindful of listeria: good.
Trying to get people to be afraid because of the colour of their skin: abhorrent.
The system of random checks is an effective system for accomplishing both.