These dungeons aren't intended to be hard. They serve a few purposes but being hard isn't one of them. Also please remember, these dungeons aren't even intended to be challenged at ilvl 110. The gear we have removes a lot of the challenge, just like in Coil. Second Coil was hard in 90-95 gear, in item level 110? Nope. Same will happen with Final Coil, at the moment it's very challenging and meeting the DPS requirements is rather challenging in 110, in 130 that will be a different story. The same is with the dungeons. Perhaps go and challenge the dungeons in their minimum item levels and see what you think of them then?
Anyway, the purposes of the dungeons at the moment:
1) Easy content for everyone to enjoy without much difficulty
2) Level 50 starter gear for new players/alternative jobs
3) Tomestones
The only thing I dislike about the current system is that to max my Tomestones I don't really have many options. The options I have is either dungeon running or doing Frontlines, the latter of which has horrendous queue times and some changes they made that put me off playing it almost completely. Sure Final Coil gives me 30/turn but that still leaves me with a tonne to gather.
But atleast in the current system, with duty roulette I basically just have to run expert 6/7 days of the week and I will cap my tomestones.
As for the speed running aspect of them, even with the limitations they are insanely fast. If you find them too easy and too limited, push your party more. Drop shield oath/defiance, have your black mages bring ethers for triple flares, have your healers stance dance, heck, if it's so easy, don't even bring a healer, like lucrezia did with Brayflox HM to get a 7:55 speedrun of the entire thing: https://www.youtube.com/watch?v=aRnkWpx8F3c There's always something you can do to make the dungeon quicker and perhaps more enjoyable to yourself.