Because Forgall and Ozma are well designed fights (though I wish tanks would keep Forgall in the middle of the arena). While we wiped frequently to the two bosses (and eventually getting Duty Failed), we all communicated with each other and tried new things. It was rewarding, despite losing. Every other 24-man raid I don't think there was as much communication...

Now if the fights were all like Cloud of Darkness, then it would have been bad. Cloud of Darkness is easily the worst fight in FFXIV.