This argument of "Usenet vs Reddit" has a kind of anachronistic feel to it. There was over a decade between Usenet being passé and Reddit gaining popularity. Alternatives to a Reddit at the time of its emergence were other relatively new "social bookmarking" sites like Digg and del.icio.us, and the old standby forums mostly running PHPBB and vBulletin. I came of (internet) age during this time in the early 2000s and never used Usenet; nobody I know did, but we had online communities before Reddit. Many of them even had point systems and badges and other little gamifiction elements that were often idiosyncratic and tailored to the specific community.
It's lack of use by non-technical people was likely due to lack of exposure and/or access rather than lack of appeal.