Skins for a champ I DON'T WANT, or a champ shard for a champ I ALREADY OWN

**I'd like to get a skin for a champ I actually enjoy playing or a champ shard for a champ I don't own! **

Why not make it more likely to receive a skin for a champ the higher your mastery of that champ, how much you played that champ vs others, or how much you've played of a champ recently?

** Also, would it not be a good idea especially for players who have played for awhile (but not long enough to have saved up 8 billion Blue Essence) and are just GRINDING **(which is much harder when you can't get Blue Essence every game) for new champs to just make it way more likely to get a champ shard for a champ that you don't own?