The difference is that on Reddit you're not giving any monetary value with the upvote's action, which is even worse.

riberet19

I see this same phenomenon on reddit.  Topic with 30 upvotes, top comments with order of magnitude more upvotes.

I think people open topics in a new tab, engage with comments then forget to upvote the topic itself.

SN Zapping and Posting Fees

siggy47

I see this same phenomenon on reddit.  Topic with 30 upvotes, top comments with order of magnitude more upvotes.  

I think people open topics in a new tab, engage with comments then forget to upvote the topic itself.