I'll just say as someone relatively new to PSO franchise, i did play the original PSO2 but i never really got invested. Now i really like NGS but... the OP is right. As someone who has played Every MMO you can imagine. From Ultimia online to City of Heroes, to more popular WoW and FF14 NGS just pales next to most of these MMOs. I mean like at City of Heroes... at launch it had HOURS and HOURS of story content. Sure you spent alot of time grinding up with your friends in the various parks or the sewers BUT the story was there... and that was a very old MMO.
NGS put next to any modern MMO feels very bare bones and lacking, and are alot of features that just feel old and dated. The UI especially just doesn't feel modern, or up to date. Why am i jumping through dozens of menus to do basic things... Its really off putting and the whole BP crap, why is this locking out story quests? It all feels like gating to hide the fact there is very little actual content at the end of the day.
Basically i'll probably finish the storyline and come back in winter... and i think alot of people will end up doing that.
can't disagree with you as the OP stated, anyone with ample time on their hands can finish the entire story quickly and most other content in less than a day. Hope this is a learning experience to say the least and the next update makes up for it.