They overwhelmingly make their money off of Google Adwords, and adsense users get to keep 80% of revenue from clicks. Adsense users don't have to pay anything up front , just a % of revenue is deducted from earnings. Adwords customers pay google lots of money. So, this should help explain why a lot of termination of adsense accounts is probably automatic based on criteria which often times "assumes" (that users click their own ads) Keeping adwords customers happy is one of their top priorities. But they should care about adsense customers to help with their own reputation. They should give themselves logical reasons to care about us... maybe they wouldn't be so laid back about letting us users of adsense go if they kept 50% of revenue rather than just 80% (or whatever it is) ? share your thoughts with what I wrote...
Google cares about people sending them money, not people they are sending money to. It's a simple as that.
AdSense users are publishers and not customers to best of my knowledge. Google gives you 68% of the revenue. ( 32% is a fare deal for managing such a large network) AdSense ban is not purely due to "invalid click". It is a misconception. They are banned for not following AdSense TOS. that includes copied contents, PPC( porn perversive and casio) contents, putting adsense in login page, displaying adsense in a page with little content, click fraud( different from invalid clicks), too vigorous SEO or balckhat. A company can not be blamed if one can not find time in reading and understanding it's TOS.
True they don't want to give away money. They also are really selective when they accept adsense members. Took me three tries.