So you're happy to punish 10% of students, for no fault of their own. You'll trade a moment's distraction, for a paid-for day's learning.
That, is a lack of empathy. Especially as for about the last hundred years universities have had a process that allows for the necessary flexibility.
To take this to the extreme... Should we simply fire everyone who is late to work, without reason? If someone else causes a car accident, should we simply revoke the licenses of everyone involved, regardless?