Clear
CliffyB's Cock Holster
Chains of Promathia?
Junk level-capped zones.
'Kings' with 3-5 day repop windows
Absurd difficulty curve in storyline BCNMs
The huge middle finger that Absolute Virtue represented to the entire playerbase
The man who made these things AND XIV 1.0 does not deserve another dollar from me.
Counterpoints:
The CoP expansion rolled out pretty fast, and contains some of the best and most intricately designed zones in the game. There's also a density to the content that simply isn't in any other expansion, every chapter contains a number of NM fights, puzzles and gimmicks.
Level capping while inconvenient, at least kept the challenge high and gave people a reason to craft/buy/sell/keep lower level gear. The alternate scenario being what happened after they removed all the level caps and added level-sync, low-end gear became impossible to find making it really difficult for newcomers to level up.
Ground kings were a RoTZ element, and whether you liked them or not, were a very popular event for many, many years. And as recent changes have shown, shifting from a horizontal to vertical progression model, simply isn't that quick a fix.
That FFXI was hard and unforgiving was part of its appeal. Play the game today if you want to know what the pro's and con's are to removing most of the challenge. Its night and day different and of course, players are still complaining!
AV simply wasn't relevant to most of the player-base. Its drops simply weren't that good, and most shells struggled with the lower-tier jailers who's drops were even worse. Mid-tier groups got Limbus to satisfy their end-game cravings, which was more fun and rewarding for most of the participants.
WoTG was where most of the mistakes were made and where the user-base shrank the fastest.