Because its a subject people feel strongly about so they like dragging it into everything. You see it with all sorts of topics. For example, almost anything to

Because its a subject people feel strongly about so they like dragging it into everything. You see it with all sorts of topics. For example, almost anything to do with the UK will result in someone going on about Brexit. The current US president is mentioned at the slightest excuse. Any kind of polarising issue, really.