Why can boss fights be started while first-timers are watching the cutscene?

[Llyren]

No one can force you to skip cutscenes.

The participating in the fights bits, yeah everyone went through that once.

Main scenario first time is for watching cutscenes. Second time is for learning fights.

If the boss fight could not be started until the cutscene is over then the instance could be held hostage.

I'd prefer for it to finish while I am watching a cutscene, then participating in a battle, but I've already watched the cutscenes... so I'll play with the monsters a bit while others watch.

[Vidu]

If the boss fight could not be started until the cutscene is over then the instance could be held hostage.

You would be right and I kinda thought the same but OP already offered a solution for that: the cutscene would simply run automatically aka the first-timer whos watching it wouldnt have any influence on who long it takes - after a certain amount of time it would simply be over. Might not be great for someone who's slow with reading but you could always rewatched them in the inn - in your own speed - and still didnt really miss them while they actually happen. So with this setup the party couldnt be held hostage - they'd just had to wait for a few minutes.