There is good arguments on both sides, and since i haven't played a many MMOs i can't coment on if this is good or bad so i'll just coment on what i read.
I see some saying that crafting will become useles, and i have to agree there, though it'll depend on how good the dungeon, rare/ex, droped gear is. Anyone that plays XI today will tell you that crafring has become useless to the point that farming for mats has become pointless.
Now in XIV 1.0 there were slots that you had to fill them with crafted gear, cause the rare/ex wasn't very good. E.G if you were a THM/BLM you were better of with a crafted/melded head piece than anything else, same was for the legs, there was no good leg piece (except for DL?). If that continues, there might be a spot for crafters, but let me put a situation.
Lets say i don't like to craft, i just like to fight. As it's been stablisshed, we'll be doing a lot of quests to lvl. So we'll have more gear that we can use, no point for crafters there. I got to lvl 50 i got my AF (that for most ppl will be enough for endgame), so no room for crafters there. I got a little money i deside to spend on a melded gear, double meld will be easy to get so there'll be cheap, so i get a triple meld. I'm happy with it and i do some endgame. Some times passes and my triple meld is starting to get old, i'm wanting something with more power. I got the money so i wanna get a quad meld, but wait, there is a problem, what do i do with my triple meld? i can't resell it, i can't give it away to a friend (wich defeats the idea that Yoshi-P had by giving us PLing, to help a friend get tough to play at the same lvl), i can't even pass it to a character in my own account. All i can do i sell it to NPC for set price by SE(a price that does not reflect the value of the item) or i can turn it into materia (a Materia that would be a the very best 1/2 of the value of the materias in it, not to mention the tries it took to make). Now i'll wonder if it is worth it? or my the next time i wanna buy something if it's woth pay X amount for something that i'm gonna get X/10 to 30 or more. That will end up lowering the price of everything crafter/melded because ppl won't be buying that much.
Now crafter's only source of real income will be expendables (Stalone, Schwarzenegger, Jet Lee, ETC), but wait, there's no more arrows, there'll be no bullets, there will be no thrown weapons. Only food and pots, so yay for alchemists and cooks, the rest will make do.
Now the other thing i see is that SE is sending mixed messages with this. In 1 side we have items that once used in battle/craft/gather won't be able to be traded/sold in AH. And on the other we have the Free Companies that will have a commun storage for players put and take out items. So if i take something from the FC's storage is mine for ever? IDK how will this work. This will be a great tool for an ass to grab items that were ment for everyone and steal them or make a simple mistake and screw someone else who might need said item.
And i see ppl saying "we need to destroy items" and where up to some extend this is true, this is bound in the premiss that no new players will come in and old players go. There will always be recicle of players, old players that leave and don't get rid of their things in case they wanna come back, and there'll be always new players looking for gear.
For the destruction of items, i propose 2 Ideas
1) In the real world when you buy something used, you know it's used, and for that you pay less than the same thing new. So i say, put a counter on the pieces, so every time you sell/trade it, it goes down and when it gets to 0 it turns into a Materia. you also have the option to make it into a materia before of cource. the higher the number the more it'll cost, but you'll still have a chance to resell it or give it away when you are done with it, but you'll be more causious to lend it though.
2) As someone said back there about a pirate game that has perma-break of gear. That but you are able to sell it, lend, and give it away. the perma-break bar would have to be quite long but it'll eventually take all the gears out of the game.
That's what i think on the matter, and as a final word i'd like to ask anyone who knows of examples of games where they have this binding gear thing and have a succesfull market for crafter gear and related items (ingredients for said gears) and if you are againt it, provide some examples where the market isn't successfull.
P.S: Sorry for the wall of text XD