I think people who complain about wanting to sleep are weak
Why do you say they are weak when complaining about wanting to sleep?
Because strong people don't need to sleep.
Even though you may think people who complain are weak, you still should not call them names. They express themselves differently and should not be judge because of that.
I think I can say whatever I want since I don't get any sleep.
But how you feel doesn't impact or relate to how others feel in their moment. It's much better to be empathetic instead of passing judgement.