Actually, rssing.com has nothing (directly) to do with your RSS feed. It seems to be a content scraper and mirroring/archiving "service," if I'm feeling charitable. And it looks like a site that wants to redirect users to its copy of users' content in order to get ad revenue if I'm feeling less-than-charitable.
In fairness to Google, that's always been a problem, and even in the good-old-days in which keyword-based searches were more effective, there were content aggregators that would copy the entire contents of phpBB-style bulletin boards (and USENET newsgroups) in order to rehost them and get clicks.
On the one hand, I want to say that it's precisely the sort of SEO/spammy practice that Google should be deprioritizing in search results. On the other hand, sometimes these copies/mirrors of content are the only extant copies of content when an original blog goes away. Although the motivations of the owners of these sorts of sites may not be as pure as that of archive.org, the result for the searcher is equivalent: the desired information is found even if it's only a rehosted copy.
In fairness to Google, that's always been a problem, and even in the good-old-days in which keyword-based searches were more effective, there were content aggregators that would copy the entire contents of phpBB-style bulletin boards (and USENET newsgroups) in order to rehost them and get clicks.
On the one hand, I want to say that it's precisely the sort of SEO/spammy practice that Google should be deprioritizing in search results. On the other hand, sometimes these copies/mirrors of content are the only extant copies of content when an original blog goes away. Although the motivations of the owners of these sorts of sites may not be as pure as that of archive.org, the result for the searcher is equivalent: the desired information is found even if it's only a rehosted copy.