No one is asking him to stop being a human. As a footballer there are plenty of appropriate periods to indulge yourself, however 48 hours before a match is not one of them whichever way you look at it.
If you’re a serious footballer you give yourself the best chance to perform to the best of your ability through proper preparation.
The wage Iwobi is paid a week, most people don’t even earn in a year. When you actually think about it we’re not asking him for too much to be consistently professional.