Does Google lower site rankings which have links from sites which Google disapproves of? This doesn’t seem fair. That is why many people think it can’t be true, especially since Google’s web site states: You can make money without doing evil.
After all, we have no control over who links to us. It this were true, one of your competitors could easily provide a disapproved link to your site and lower your rankings.
What is Google’s main goal?
To provide relevant search results. If someone comes along and provides superior search results Google will loose its searchers. When that happens, there will loose the first half of their statement above: “You can make money…”. Therefore, we can conclude that Google will do anything they can to improve their search results. That way, they serve their own best interests and do what is best for their clients. Let’s not forget that their clients are the searchers–not website owners.
If Google concludes that they can improve their search results by lowering rankings for sites which have certain incoming links—what do you think they will do?