In many cases, a person's principles are clear from what they say and do. That being said, a refusal to align one's self with a movement is often construed as supporting the other side. There are many reasons for refusing to align: a preference for independent thought, a realization that ideological movements change, an understanding that one's own principles shift (while labels often stick), or simply not buying into some fundamental points. None of that seems to matter when issues are polarized.

From chariot races to football clubs, real politic change happens through sports.

Here's an account of the famous chariot race riot in ancient Constantinople:

https://en.wikipedia.org/wiki/Nika_riots

Humans will make an identity group worth dying for over anything.

Bread and circuses was a state policy in the Empire for a reason.

Nobody is willing to even come to the table anymore because of how totally wrong and evil they see the other side as. Which is kind of the point of the article.