Binding items won't help stimulate cash shop purchases (for the purposes of hoarding and selling) from old loyal cashers with hoards of items and would instead discourage them since nobody wants dupes if they're account bound and unsellable, and would also screw over previous hoarders (both cashers and non cashers) with replicas, and future hoarding for anybody wanting to do so which could benefit the economy as stated in the next paragraph. Even if this would encourage cashers to buy bound items since they're unavailable in the auction house (and literally force non cashers to become cashers if they can afford to and have the desire to do so), it would still feel forced and less valuable if they're untradeable with no freedom of trade or sale and could reduce cash shop purchases. This will also force the release of new items to allow cashers to continue buying from the cash shop when the items are bound, unlike when they aren't bound where items would be released with leisure and when old ones lose value over time (except consumables that aren't guaranteed to lose value).
And in regards to hoarders, hoarders are needed because they're sometimes useful when they help prevent item value drops even if item monetary value drops could help new players buy these overpriced items (overpriced during inflations or mispricings only) from the auction house, and attacking hoarders (even through non-binding means) will negatively impact the cashers that buy replicas for quick zeni and farmer hoarders.
Binding however, will not reduce values, but will nullify the monetary value completely when items are outcast from the auction house. So due to this it won't be preserving their values like intended either and as said above will stop cashers from buying the same items again but not new items. Non monetary values like the supply won't be retained with exclusivity either, even if the supply cannot be distributed to different characters the number of the specific item will still be there.
And in regards to other implications, binding will only prevent new players from ever getting these bound items instead of simply making it take a huge chunk of their time to farm the cash necessary to purchase them from the auction house; and binding will also screw up item transfers to new characters + accounts and would just force us to start from scratch and multiply our efforts for no good reason.