It's about time some sort of 'rules' were enforced, and Shanahan has done just that. As we've read, Kadri's lateness is not the only issue here. Obviously there were other transgressions at play here.
I like Nazem, he has tried adapting to Horaohek's system perhaps better than some of his other teammates, plus he carries with him plenty of talent, which we're already seen displayed as the team's best centre.
In the real world, usually an employee would have been relieved (fired) of his or her duties, or something thereof to a certain extent depending on the situation, etcetera.
In the sports world, different organizations react in their own manner either via a fine, demotion, trade, or what have you. Considering that Kadri has been called an important part of the team by Shanahan and well-liked by his teammates, and is still at a young age, the 'punishment' cannot be deemed all that harsh when compared to other situations.