It's both Google trying to force web sites to help their algorithm and spammy sites trying to exploit the current algorithm that are causing these annoyances.

I suspect neither would be a major issue if Google modernized their algorithm to take into account (mostly/only) which links people actually clicked on rather than what is linked from where. They'd only have to be able to distinguish people from click-bots, which might be easier to do with some confidence than recognizing the intent behind a particular link (spam/SEO or real information for visitors) - I hope they are already able to do this, for the sake of AdWords customers ...