The primary responsibility falls on the prosecutor. The prison sentence they sought for Swartz was not by any stretch justified. This injustice seriously endangered not just Swartz's mental health, but his prospects for a fulfilling life, even had he lived.

A prosecutor doesn’t seek a sentence until after the defendant is found guilty.

Moreover, judges don’t care about prosecutors or what they think. And, sentences are largely determined by sentencing guidelines.

Rich white kids with no prior convictions don’t go to prison for stealing library books.

The prosecutors choose the charges, and did not have to choose charges that carried a maximum sentence of 35 years, which is almost a death sentence.

What judge would have given the max sentence for this case?

The judge doesn't have to give the max sentence for the charges the prosecutor chooses impacting the sentence given.

No-one exists in a vacuum.