Ask HN: Do startup accelerators have any correlation with success?

I'm not seeing the ROI from startup accelerators including YC, Techstars, etc. As I see it reasons for possible failure of startup accelerates include:

1. Focus of accelerators of picking founders based on gimmicky characteristics like their age over vital characteristics like their domain expertise.

2. Emphasis of accelerators on coding rather than sales solving all problems. Maybe this is unfair and rather, accelerators simply don't do a good job of realizing which founders want to code vs sell their way out of the trough of sorrow.

3. Accelerators picking startups based on some insider connection. I'm no financial guru but shouldn't you NOT let emotion control your money?