You could say that I feel rehabilitation is preferable to incarceration with minimal opportunity for reformation, yes. Malicious forethought precisely the issue.
We can clearly say that this man is operating outside the boundaries of acceptable behavior. One might even say that he is a bad person. I would, however, strongly assert that this punishment is horribly disproportionate to the crime committed. One might even look back to Leviticus and find preference for an "eye for an eye" than 18 months for inappropriate conversation aimed to make another party uncomfortable. If I was the judge, I would simply insult his mother and be done with the case.