The Monk Temple

[enil]

SNIP

FFXIV will count DoTs full duration damage even if the mob dies early. Your summoner is probably getting a lot of non-existant damge from FFXIVAPP this way.
Trash is really important but if you care, you should get your tank/healer to chain pull. Monk AoE is not that bad, we may not have burst but Rockbreaker is probably the most GCD/resource effecient AoE attack available, use this when clearing trash to maximise dps. Doing AK without any downtime keeps your GL uptime high and lets you finish the dungeon much quicker.
You said yourself you beat SMN on the last boss, not sure what you want to complain about - if Monk was buffed further wouldn't this be more unfair for other classes?

In all 3 boss fights in AK, the only time GL should drop is if you get bombed by the last boss, every class loses lots of damage doing this anyway it's not unique to us.