IMO encounters are spread to thin. If we compare WoW to FFXIV over the past year (I do this, because I feel raiding is the thing WoW does best) - WoW has added Hellfire Citadel and FFXIV has added Gordias, Midas, Bis, Rav, Thor, Seph, Void Ark.
In that, it sounds like FFXIV has added way more, but then let's break it down some more.
Hellfire Citadel 13 encounters
WoW: 13
Gordias 4
Midas 4
Void Ark 3
Bis 1
Rav 1
Thor 1
Seph 1
FFXIV: 15
Again, it looks like FFXIV is in the lead. However, then if we consider all the difficulties:
In WoW, there are 13 in LFR, Normal, Heroic and Mythic difficutly - (all of which are currently relevant.)
In FFXIV, there are 3 in 24 person DF, 8 in Normal, 4 in Trial and 8 in Savage - (3 in 24, 4 in normal, 1 in trial, 4 in savage which are currently relevant)
So, while FFXIV has more encounters (takes more time to design graphics, story etc.) WoW has more encounters per difficulty tier. This provides more encounters for each type of player to enjoy. If you are like me, who fit most well into the Trial level of difficulty, all you have to look forward to is 1 fight every few months that drops 1 weapon.
It comes down to three major issues from my perspective.
1. Uninteresting and very restrictive loot tables (i.e. in LFR you can get 1 item per boss so 13 items per week, where in 24 person DF you get 1 item per week - or in trials all you can get are weapons, etc.)
2. Massive dilution to appease a mass audience, resulting in very little content for each market
3. Rapid updates which make previous content irrelevant, rather than adding onto previous content
Then, there are some more personal issues:
1. Uninteresting story
2. Bland colour palette
3. Boring direct-to-arena queues
4. Frustrating fights that seem like they are designed more to be difficult than they are to be fun