I'm young-ish (25) and I attended the other Monday night.
Most young people come with their parents to the game, so if the parents didnt go then that will obstruct the young one's too. As they wont drive and Belle Vue aint the easiest or cheapest place to get too without a car (2 buses/taxi etc). Young people also like you mention have other things to do when they get home from school/college project work, actual part time jobs or GTA
or what not.
Everyone knew that event was a handout plea session and what money have the younger people got to give. How much spare cash did you have when you were 18 to donate, buy platinum ticket, have direct debits etc.
Some will have the capacity to do so, most won't.
Not as clear cut as young people couldnt be bothered.
Also most young people have access to forum, social media, to understand what is happening at the club (doubt all the 60+ who attended that meeting can find out whats happening any other way than at such a meeting)
Small rant over.