We have to. Short of arguing on first-principles, agreeing on them, and then using those principles to evaluate everything done on both sides, this is one of the top mechanisms we have to bring a spotlight to the contradictory mess we have on our hands.

Personally, I blame lawyers and prosecutors. A law should be simple, easy to evaluate if it was broken, and always prosecuted. And when it comes to punishments, they should be explicit and without the possibility of being altered.

We've gotten too complacent with making all these arbitrary rules, then fiddling with their non-enforcement and severity by virtue of reduced sentences.