Kings and a lot of the overworld NMs were a terrible idea, in my opinion. I'm always surprised when people look back on them fondly, because most people I know found them boring and tedious (not to mention sometimes immensely frustrating thanks to bots and That One LS full of jackasses). And because sitting in town for hours attempting to get a party/find a tank and healer to make a party to level and coming up empty-handed was so much fun.
But seriously, I mostly enjoyed FFXI back in the day (trying not to look at things with rose-colored nostalgia)... but I think that day is done. There just isn't as much of a niche for the punishing, extremely grind-y games anymore. Thinking back on it, some of the most dedicated, hardcore types I played with.. work full time jobs now, have families to spend time with, other responsibilities, etc. They simply don't have the time or drive for a game like old school XI, and I think that's a trend with most MMO players as a whole.