@Kdom:
So what were all these characters for if it is not to focus on them. Look readers, i put the most powerful people of the serie in one place but i will just show you cameo because it is to early. This was just a teaser. See you in 20 years for the real thing !
And you ask me the reasons why I am unsatisfied ?
Because if it focused on all these characters at once it would take the spotlight away from Luffy, and people would instead complain that Oda wasn't giving enough time to the main character. Look at Ichigo in the Final War arc; most everyone barely cares for him now at all because he was barely shown in it. The purpose of all these powerful people being featured was to show Luffy how out of his depth he was at Marineford and give him something to strive towards in the New World. If all the new powerful characters got full on development, it would render them completely uninteresting after the timeskip because we've seen all that they do.
Instead, we got a good peek at what was in store: the personalities of the three admirals that gave them their driving traits in the New World, Doflamingo's big speech, Mihawk displaying that he was still the greatest despite big competition, the renewal of Crocodile's old dream, Buggy's comical rise to power, Jinbe's loyalty toward Luffy, Moriah's downfall signifying the strength needed to compete, the end of an era with the wipeout of the Whitebeard Pirates, previously the top pirate crew in the world, and of course Blackbeard's rise to power all set up their own New World plotlines which have all become interesting, as opposed to tired has-beens just being in the New World for the luls
And the war was actually pretty full of casualties, with mooks dying left and right. Yes, they're mooks, but the implication was that nearly everyone would have died had Coby not interrupted everyone when he did. Whitebeard came to Marineford to save Ace, not to kill as many Marines as he could. And when Ace died, and Whitebeard got serious against the admirals, he destroyed Akainu and would have likely killed him had Blackbeard not shown up when he did. And Whitebeard was also very sick at the time.