diberry - 3:24 pm on Nov 8, 2012 (gmt 0)
Why would they consider them low quality if your users find those sites useful? That's the point of this ranking system.
It's appears that how your visitors interact with the sites you link is only one factor, though - a factor that might get outweighed by the site's keyword stuffing, footer links, etc. In which case, Google may ding you for linking to them even though your visitors use them.
I would hope that's not the case - I would hope instead Google would ding the other site in that case but NOT ding you because it can detect that your intention in linking the spammy site was good. But unless I missed something in the article, it's not clear how Google will look at these traits in addition to other traits it evaluates.