A big part of that problem is that 'everyone' has a maxed out crafter these days so the little stuff just aint worth putting on a vendor as it'll be their this time next year. exception of a few items like recalls, apples, petals, ect.
The craft part of UO died a LONG time ago. (AoS killed that off)
Now its only new and exciting when a new skill is released....well for a couple of months atleaste.
Imbuing was the last big thing (Dev's raved about it at the time and ignored ALL the comment's on how it will ruin the craft market) and even that's died allready cos everyone thats wants it, has it.
Those that don't, probably never use the stuff anyway.
The only real part of crafting still left alive is Gathering and that's only cos peeps have so much gold they can't be bothered gathering it for themselves.