I like Wikipedia’s definition of politics: “Politics (from Greek: Πολιτικά, politiká, 'affairs of the cities') is the set of activities that are associated with making decisions in groups, or other forms of power relations between individuals, such as the distribution of resources or status.”

Any subject arising from the interactions of people can be viewed through a political lens of some sort, but the saying you’re objecting to is typically used in the context of the coded attempt to censor or ignore unpleasant news as being “political”, which in truth usually just translates to “I resent being forced to acknowledge this.”