Why should I be excited for Grind Parties?

[Verecund]

In order for "slow leveling" to actually work these days, there must be plenty of varied content filling in the game itself. (*this argument only applies to countries outside of Korea) Not that I'm complaining about that aspect at all, but this game definitely hasn't come close to filling that bit yet.

Also, one major problem with slower party-based leveling is that if the game fails to have solid hooks to keep new players wanting to level, people aren't going to want to stick around if they join a game half-way through to another expansion and find they have to solo a party-based leveling game (because everyone is at max level).