We want judges to have discretion. It is an integral part of the justice system. There are some cases that require a judge's keen eye to recognize a person's background, the circumstances of the case, and whether there is a special need to sentence harshly or lightly. These people went to law school and practiced for years. We assume (although not always correctly) that they are in the best position to pass down sentences from their bench, a position that involves them handling dozens of cases per day.
Every case is different. A chart dreamed up by politicians cannot predict a just and uniform outcome for every single defendant that might possibly result. So the legislature tells our judges that they can sentence anywhere between probation and 93 days in jail. The judge did that here, and she didn't do anything wrong. Judges are people too, and they're all different. Therefore they are going to have different insights and biases. Jalen would have ended up with a different sentence in front of a different judge, but such is the risk you take when you expose yourself to the criminal justice system. Equal and uniform justice is impossible, so the best we hope for is that, as a whole, the system will eventually spit out enough cases that average out to a just and orderly society.