FUCK reactions and FUCK people that obsess over them.
Generally the only useful thing about them, is that you can gauge how well people fit in. Even then, this isn't foolproof as this taken as a fact could be used as a part of some gayop. Null is mostly right that people are finding the dopamine hit addictive and were adapting after the "Reaction Score" was removed. It is pretty adamant in the userscript thread (where Null announced disabling the page) that most people were just coping as to why this is a bad thing after the consequences of the dopamine dropoff were felt. That's why most of the initial arguments were shit. A better way to gauge fitting in, without having to rely on reactions - would be some sort of activity metric that works for lurkers too. From what I've seen, some people tend to use the "Joined date" as a helping metric too.
From where I'm standing, Josh wants to turn this in a late 90's Web 1.0 warez forum, while others here want Reddit and updoots.
I guess I just want to read more arguments, which aren't straight cope, of why reactions are beneficial.