• DEC-B makes the game more complicated for new players
• DEC-B will never go away again and will remain a burden that once had a use case but is now just dragging along (like vouchers which should never have survived the CL presale)
• DEC-B requires development effort and the contract requires maintenance resources that should better focus on the game
• Giving an extra payment for land a new currency name doesn't make it less of a payment (especially since nobody will ever know if there really was a discount applied or if just the base price was moved up)
• DEC-B will indirectly create more DEC by converting vouchers to pseudo DEC

I do not see any way this is a good idea

Wasn't the message "no new tokens, no new sales, instead deliver on promises"?