If our society decides it is necessary to act with the full weight of the law behind it, then it would seem better to have the information available for the public to verify than not. I'm not saying it is all great, but that it is far better to have information available so that things like average sentence length for a given crime based on demographic and psychographic information can be queried by all. If a city that is 50/50 male/female and 20/80 black/non-black finds their speeding tickets are 70/30 male female and 35/65 black/non-black, then it may be worth investigating to see if police are being fair who they give warnings to, who gets reduces tickets, and who gets neither.

As for major privacy concerns, it is generally the more major crimes that have the larger issue with the victim being known. Knowing that some one was the victim of mischief vandalism is far less a privacy invasion than knowing they were the victim of sexual assault of a child (and even hiding the victim's identity often doesn't do more than hide the name from a passive search).

Then there are the benefits that other posters have raised, such as being useful for knowing past decisions used even in minor trials.