Kassadin Skin?

The last Kassadin skin was released in 2011. Meanwhile, champions like Nidalee, Katarina and Annie are receiving new skins every few patches. What's the deal with this? It's both unfair and seems ineffective.

Anyway, as a Kassadin main, I feel pretty cheated sitting at the edge of my chair patch after patch hoping the next skin released will be a Kass skin... For threeyears... With no avail. I'd really appreciate hearing some thoughts on this.