A felony conviction, three years probation, 400 hours of community service, and a $25,000 (inflation adjusted) fine for a novel non-violent crime with no personal material benefit isn't exactly "got away with it"
He didn't reoffend (as far as we know), and in fact went on to become a highly-contributing member of society. His crime was not so egregious that recompense was impossible even in principle. I don't see how a harsher punishment for him would have produced an obviously better outcome. I think it would be more productive to argue that people who commit similar crimes should receive similar punishments as this, rather than arguing that he should have received a harsher punishment.
Everyone hacked. When the internet was connected to Sydney University early 90s, all the students were grabbing Stanfords /etc/passwd files and peeking at the open X displays of people in Sweden. Etc. All for fun / curiosity.
You can be sure that even rtm's Dad did similar, perhaps confined to his lab / peers.