As a handful of posts have mentioned, there are absolutely legitimate reasons for leaving early. Personally I’m lucky enough that I don’t have pressing family or work issues that cause me to have to leave early but I won’t judge someone who does.
And if this is to be enforced as some of the people on here want, then I assume that no-one moaning about this leaves early to grab a pint at half time, or is delayed getting back to their seat for the second half? As that is just as bad. Leaving to get back for family seems more important to me than someone not being able to hold off for a couple of hours and wait for a pint until after the match.
Or shall we start attaching sound meters to people to monitor their singing and or levels of abuse directed at players? Perhaps we can start to vet for the real fans and get rid of anyone who doesn’t measure up to the standards set by a collective few who never, ever let themselves down.