Need to address the Eureka in the room.

[purgatori]

Let's see now, we have dangerous mobs that you can't just pass by them without fearing you'd get killed by them if you're not careful. Requiring you to be in a group to do any kind of activity, which is why it's an MMO. The interaction between players when they group together to spawn an NM and the NM train. Even if it's grindy, it's still less grindy than the previous relic style and there are lots of people who actually got their relics in each zone in 1-2 days (except Pagos, cuz it sucks). No flying (that's my personal opinion but it's not like it's a deal breaker or anything to me) because flying limits how the zones are made in order for them to take into account what you can see when you're flying really high (perhaps after dropping PS3 and 32bit support we would see some improvements in ShB zones). The logos actions can create a very fun experience (like reflect farming). Having a different leveling system, which makes you explore the zone carefully and not just go wild just because everything is at your level and also, once you do it, you don't have to repeat that step for all other relics (unlike the previous style). I can cap my tome stones easily. And of course BA.

Is it a perfect content? I wouldn't say so. There are things I hated about it like not being able to level sync with your party to be able to efficiently help your low level friends. Being in an instanced zone. The quests with Krile are boring and only each couple of levels (at least they should add more side quests that require group work).

The things I'm neutral about and doesn't bother me nor do I care about are deleveling when you die, and the mount restriction (although it gives big benefit to multi seat mounts and also creates a nice atmosphere when high levels offer low levels a ride to help them pass dangerous places to NMs).

MMO ≠ grouping. When people conflate MMOs with grouping, this is less an accurate reflection of what an MMO is and more a statement about someone's preferred way of playing an MMO. There's nothing wrong with this preference, of course, unless that person thinks that because they exclusively enjoy group content, then everyone else should be forced into grouping whether they enjoy it or not. Unfortunately, this is usually the case when someone is advancing some form of the "because it's an MMO" argument.

For me, the hallmark of overworld/open world content is that it can be enjoyed by an extremely diverse range of players; whereas, to my mind at least, instanced content is conducive to more narrowly-focused content that appeals to smaller subsets of the community. Now I guess whether Eureka is overworld content could be debated (though I think if it's not, then perhaps it should have been), but it certainly does not do a good job of catering to a diverse range of players—if that intention was even remotely present during its development.