Removing cores is almost certainly a massive coding headache and would cost a tremendous amount of dev time taking away from the creation of new content. More than likely removing cores requires touching likely hundreds if not thousands of elements in the games, recalculating drop tables and rebalancing progression. Maintaining a value for infusing gear that prioritizes either earning higher level gear of the same type (which is how I infuse almost all of my gear) or the careful expenditure of cores while providing more direct paths to acquisition is where the goal needs to be. The gunsmith bounties will help, and hopefully one or two more direct paths a la Valor/Glory/Infamy ranks/subranks should help achieve that better balance.