You can't just handwave away 90% of the content and claim that all these sites are really about the links.
For God's sake, you're citing reddit, a site renowned for people reading only the headline and then jumping into the comments to socially engage about the topic.
Or let's point to "we did it reddit!". That wasn't a social collaboration? Or r/place? Or AMA?
Yeah, if you ignore all of the social interaction, reddit is a link aggregator. But if you really think reddit is equivalent to an RSS feed, you're either being a troll or just oblivious.
Do you really think there's an important distinction to be made or do you just not want to admit that you're no different from the people who scroll Facebook all day? If it's the latter, maybe it's yourself you're more upset with than the term.