As has been said before, most people will take the path of least resistance and the quickest option. But that doesn't mean the quickest easiest option is good for the player or the survival of the game itself. I still lvl up in Aydeewa sometimes, but its hard to find other ppl who even know where it is.
Also you neglect to mention new players, players who never did any of the oldworld partying, join FFXI and you say to them choose between "get lvl 30-99 in one single day, while asleep, in dom ops, or work really hard for a year in lots of challenging fast-paced & effort-based battles allover Vanadiel, to get those same levels" and those new players are going to go with the first option.
Its the fact that in the old game we only had the option of legit partying, which made us do it, and while doing it we got good at the game mechanics and made friends etc. And perhaps more importantly, we stayed subscribed to FFXI billing for years because that is how long it took us to achieve things. Now you can get all jobs 99 while AFK, in a month, and uber SoA gear in a few weeks that is 100x > anything else in Vanadiel, you have a lot of new players who have only been in game for a few months and feel they 'beat' the game and don't know why they should bother with any content. That problem did not exist when you had to build levels, skills, and weaps/gear VERY SLOWLY, those were the 2k/server days and people were logging in to complete their longterm goals. Today is 400 people on my server, and the reason for that is they have no goals left, they outgrew the possibilities offered by Vanadiel in just a month. In the old game we played for over five years and still didn't finish all the jobs and gear we had set our sights on.
Analogy : if you give some kids the keys to the Sweet Shop and tell them to have everything right now, don't expect to see them coming back next week to buy sweets from you, because they've already got all the sweets they need. Deferred and gradual gratification = longtime returning customers.
