Yes, google adsense depends on a lot of things. Its not always the best way to monetize a site at all. The payouts are just really low unless you can bring good traffic to good key words channels.

There's alot of companies out there now just building a site together in rails, and expecting to monetize fully on adsense...

Adsense isn't what it used to be. There are still people out there doing well on it. Just be methodical with your traffic. Continually improve it and learn to understand it.