given that I have to choose between less tank or more incompetent tank, I would choose less tank. A noob tank just waste everyone's time starting from Brayflox (lv32).

If you can't tank a level 20+ dungeon without being getting complained, you will either need to get down from your high ego, stop believing you're a special snowflake and learn, or just play DPS. Tanking comes naturally to most hardcore players, but to a casual players, the concept can be hard to grasp.

The way this game's dungeon is structured, even DPS can have a huge impact on the team...but at least that's a shortfall that the other competent players can cover to a certain extend.

Even though I never yell at tanks (at least in this game...looking at a lalafell always calms me down), but I can understand the frustration especially at higher level dungeon of a fail tank or any other class for that matter.

Some of the fail players that I've seen:
-A pally with blue gear that can't hold aggro properly in brayflox, and can't work out the boss mechanics.
-Tank that can't stay dodge brayflox AOE
-A healer that doesn't cast protect.
-A healer that doesn't do combat raise at lv32
-Noob summoner who's pet keep waking up cc targets
-Tank that only hold aggro on boss and doesn't care about adds
-Healer that DPS and get the tank killed.