The problem is this is basically Bungie's asinine approach to trying to make "gold sinks" in the game. The only thing is, they messed up. Players are being able to hoard Legendary shards for just about literally anything they do in the game. Players who have played alot will have had made alot. Bungie doesn't like their players hoarding resources, so they make things expensive to serve as a sort way to force players to spend their hoarded resources. Where they messed up is that they don't give enough incentive to spend them to veterans. The players who HAVE a ton are most likely already satisfied with most of what they have and don't need to spend shards on anything. There is currently nothing in this game that is super worth spending shards on unless you're a newer player, in which case things are just too expensive. tl;dr Bungie is trying to sell rich veterans stuff that only newer players can really value.