You didnt ... I DID ... the scrolls should be bound to character. and sold through guild vendor. Selling scrolls on the AH is doing exactly what they do now .. which is not working. Crafting is not enjoyable for all .... and if your gonna make scrolls craftable then have a UMD requirement it makes no sense at all.
If your gonna make them craftable then they run the problem of high cost in time and crafting experience to give a smaller then worth while bonus? How does that make any sense?
If they are gonna do crafting scrolls they would have to allow you to craft meta magic on them. In which case they would be OP which defeats the entire purpose.