Its "demand". Think about everything you can use ore for:
1) To skill up a craft
2) to make mats which can be used to craft items
Finished products are just that, finished products..they have no use outside of their stats and MAYBE for a spiritbond. But again, those products can be made by buying ore. Ore is just infinitely more useful and versatile, thus has a greater demand, thus has a greater price. Its not so much stupidity as it is natural economics at work.
Crafters undercut because they can. Its not dumb, if they gathered all of their mats then every gil they make off of their products is pure profit. If you sell something at 180k to make a 20k profit, and I sell the same item for 80k, who wins? I gathered all my mats, thats 80k at pure profit. You bought your mats, and can only squeeze 20k profit. Even tho I sold at a much lower price, a "stupid" price, I made 4 times the amount you did...and probably sold out while yours is still sitting in the market. Nothing dumb about it, its just business.
See above. They dont ruin revenue, they are making way more revenue than everyone else selling at higher prices. Undercutting is only stupid if you can't afford to do it. But if you gathered all the mats, you can sell at whatever price you want and get a way better profit then ppl who didnt. Thats why everyone says level a DOL. Having a DOL lets you compete with ppl that have one. You will lose every time to someone with a DOL because they can go much lower than you and can still make way more money than you do. Not having a DOL is like showing up with a knife at a gun fight. You're stabbing yourself in the foot, walking in handicapped, and then say its stupid because "real men fight up close"