Class/Job System- is boring, lacks creativity and depth because they built it around casual player skill oversimplifying it instead of building the system around the potential of the class/job.
Combat- oversimplified and lacks depth there are no crowd control abilities, not a lot of support abilities and no skill chains.
Zodiac Weapons- takes to long for the casual player to get for very little gain. At ilvl 110 it should take a max of 3 weeks for a player to get if they play 2 hrs a day since new Raids and gear come out every 6 mos.
Raiding- has a lot of one shot mechanic and is unforgiving because if one player screws up he or she can wipe the entire party
Weekly Lockout- Players can down T6-T9 on a weekly basis and not get a single loot drop for their class. Players wouldn't mind a weekly lockout if one piece of loot dropped for all classes
In general anything worth getting in this game is a long boring grind for very little reward if something is going to be a long grind it will have to be the best item in the game until the next expansion.