Well for one. I do not have the time to play for several hrs on end like I did with FFXI for 6yrs+. I used to stay up late many nights till like 6am playing. After FFXI I got older, matured etc, so I am happy how FFXIV got developed. I feel a sense of accomplishment even if I only play about an hr or 2 a day. I do play more than 2hrs many nights but real life > game. Plus I told myself anyway, that I wouldnt let myself get addicted to FFXIV as well. I have played many other MMO's after FFXI, but I also played them casually.

Also, I do like a challenge but I dont mean a time sink in things to be a challenge. Make some content hard