Why are there so little level 40 crafting quests to pick up?

[Irana]

Im lucky if theres even ONE at a time at the adventurers guild on each city...

Why cant there be a rotation of 3 at least?

[Green_and_a_Half]

do the 20-35 ones and randomly they will become 40-45 ones, then either complete them and turn them in and hope you get them again.
or
finish all the synths but dont turn it in, instead abandon it and it will 100% be in the list again, then redo it.

[Irana]

do the 20-35 ones and randomly they will become 40-45 ones, then either complete them and turn them in and hope you get them again.
or
finish all the synths but dont turn it in, instead abandon it and it will 100% be in the list again, then redo it.

Wow I never thought of abandoning them ... so I could just pick whatever ones there are for 30-40 and just do em and abandon and they will be up for picking instantly again?

[Orophin]

This works well for the lower level synths since you can take advantage of careful synthesis to get good xp. But some of the allure in the higher level leves are the turn-in experience. You can get over 4k for 45-50 leves.

http://ffxiv.gamerescape.com/wiki/Armorer

This site has a list of the leves for each crafter. Sadly, I don't think crafting leves are going to see any attention until ARR launches, so you're pretty much stuck grinding or doing what leves are available.