https://learning.blogs.nytimes.com/2012/09/10/why-do-students-cheat-in-school/comment-page-18/?_r=0 A con to harsher punishments is just you are punishing students for something teachers just will not enforce. According to The NY Times access to cheat is easier than ever and teachers just do not care enough to enforce it, which is why students cheat so much. So it would not be fair to punish students more when the pipunishments are there just not enforced so students are more likely to cheat.
I believe there should be harsher punishments when it comes to cheating. If you increase how you would get punished and the severity of it the likelyhood of it happening goes down and teachers also have to enforce those rules for it to go down.