I always wondered why Shane ended up so horribly.

If Marijuana had become legal enough to be sold in stores why was Shane stuck in his miserable cop life instead of benefitting from the family business? At one point I'm pretty sure Silas says "you chose your side", if there's no law against it, why are there still sides? I've heard people say that Shane had fallen too far under Ouellette's influence to get out but still, he had to sink into miserable alcoholism instead of reaping the benefits of being related to billionaires? I thought this was an unnecessary epilogue for him.