I know BLZ is trying hard to address requests from many ppl who want gears which are not from AH. Because these ppl think gears from AH are simply made for rich. And this is not coool.
Account-bound craft will accomodate such needs. But it ignores a very important fact that you are playing Diablo, not WOW.
WOW is a social mmorpg game. Diablo is however really a gear based farming APRG game. Gears are the most important elements in diablo. ppl farm gears, play with different builds with different gears. This is why AH is a must for diablo game. Or say, a free market brings Diablo the real community life.
Account-bound craft items however will eliminate or block the market needs of gears.
The reality is that rich ppl will invest in account bounding craft to get good account bound gears. This investment used to spread in AH and eventually it would go to lucky poor players.
But now the rich players' investment into crafting will simply disappear. poor players can get nothing from AH. Of couse, poor players will not be able to afford expensive crafting. (It is really easy to understand why crafting is expensive. BLZ wants to make this as a gold and material sink. no matter how cheap every single craft is, the expectancy of getting a real good craft gear will be probably hundreds of millions of gold)
In the end, rich and poor player's gear gap will widen. And PVP will be unbalanced. more and more players will start to AFK.