I don't think that it is as simple as that. There is some form of ecosystem on the web: there are the content creators and website providers, there are the searchers, and there are the search engine providers. Each of these has its own interests and guidelines.

Searchers have quality guidelines too, though they are not explicitly published by them on the web. If a search engine delivers low-quality results, the searchers move on to the next search engine. A search engine without searchers is hardly profitable.

Most of the quality guidelines of Google are just common sense, following them will in many cases increase the usability and findability of a site.

If this has happend to you many times, you are likely doing something wrong. I have never had one of my sites banned from Google.

> If this has happend to you many times, you are likely doing something wrong. I have never had one of my sites banned from Google.

Right. So. YOU'VE never personally had a site banned, therefore others who have must be doing it wrong.

You know what, I've never been hit by a car while crossing the street, therefore others who have must be crossing the street wrong.

I've never been in a plane crash, therefore others who have must be doing it wrong.

All that means is your not trying hard enough :-)