New Tank

[Galgarion]

Marking takes a lot of time, and honestly most people just want to "get it over with".

Seconded, thirded-fourthed. Marks are for raids or semi-important special trash like the Chyme of the mountain that can wreck your group if left alone. Otherwise, the time you spend doing it is time people are standing around getting bored when they'd rather be stabbing something in the face.

[gumas]

You dont need to mark every enemy

Just mark “one” of the enemy should give you a breathing room

[Ferth]

Until you have the third move in your enmity combo you should be using your AoE enmity generators most of the time. For WAR that's a bit more difficult since their AoE uses TP instead of MP, but for DRK and PLD your initial AoE enmity generators don't even interrupt your melee combos so you can alternate aoe with MP regeneration combo pretty easily. When you are down to the final mob you should have insurmountable enmity and can continue just spamming mp recovery (or damage combos for war) until the final mob is dead.

As people have pointed out marking Targets is mostly a huge waste of time. Especially as you get into the levels where DPS start learning AoE abilities. As long as there are three or more mobs to fight, the DPS should be AoEing (assuming they can) and any DPS with DoTs will most likely be putting them on everything, anyway.