Why not? If it has headers that say it was made with FrontPage 2003 and has five thousand AdSense boxes, uses old world fonts like Arial instead of HelveticaNeue Light, uses 16-bit VGA colors like #0000ff, or has bgsound and blink tags, it should perhaps be downranked.
Because those things you listed are (potential) answers to my first question, not the one you quoted.
A search engine should not see a site written in Arial and derank it for that reason. Blink tags, sure, they're obviously wrong for accessibility reasons, but there's a huge gap between those two things - and even so, how badly should they affect ranking?
I'm saying "garbage" can be subjective, and when there are objective "garbage" indicators, it's not obvious how to deal with them. What you've listed is only a small set of indicators from a small niche of so-called "garbage" sites. And personally, I don't even want to see old or old-styled sites dismissed from the web if they have good content.
Why not? If it has headers that say it was made with FrontPage 2003 and has five thousand AdSense boxes, uses old world fonts like Arial instead of HelveticaNeue Light, uses 16-bit VGA colors like #0000ff, or has bgsound and blink tags, it should perhaps be downranked.