In the context of Dang's experiment, I think a better definition of politics is "anything which involves coercion onto an unwilling party."

Politics is etymologically related to policy. Which is a set of norms over a group. I.e. all policy is group policy.

The role of the governmemt to set and enforce those policies. Governance is generally preferable to anarchy because governance allows us to reap economies of scale. Which is invaluable in a universe of scarce resources. But due to conflicts of interest, optimal policy is often disagreed upon. Therefore, it is common that policy is forced upon one or more parties which believe the policy suboptimal, in the name of compromise.

I personally dislike when someone forces something upon me. Likewise, I dislike when I must force something upon someone else. As a result, negotiation of policy can feel frustrating and exhausting. This sentiment is where I suspect the desire for "politics-free spaces" originates from.

Regarding Dang's flag experiment. I cautiously propose the rule that: any article whose thesis asserts "a normative statement which may affect an unwilling party" is worthy of a flag. E.g. while most think of the Supreme Court as an inherently political entity, and while litigation involves an unwilling party (whoever loses), the above article's thesis is informative rather than persuasive. Therefore, I would not flag the above article. This flag policy would aim to target the inciteful, rather than the insightful.