Don't discuss politics is standard guidebook advice, isn't it? Along with don't travel to warzones, don't take drugs, always use condoms, don't utilise the services of the local sex workers etc. etc. All the things that you or I would know to never risk, but apparently some still do, hence the advice is still thought worth giving..

I gave it special mention as it's an especially sensitive topic, and you could argue that a conscientious tourist should have at least some awareness of the history of the area before they visit.