Topical SEO is another matter. Bounce rate is not widely recognized as a strong signal but topical relevance between linked sites is. How strong? Who knows. Some SEOs say total unique domains matters more. But discourse is not exclusively topical so we would expect the worlds leading commercial natural language processor to have some appreciation of tenuous topical connections. Just how little value G affords links from not even tenuously related sites is anybody's guess, as is where or why little value crosses over to be negatively valued links.