I too an passionately interested in politics. But I will not expose myself to the vitriol that is often poured by posters, (particularly on Brexit threads), with equally passionate views on the opposite side. Left or right leaning, it doesn't matter. I often go over to the other side (mumsnet) and watch with horror as posters are destroyed by post after post. On Brexit, there is only one view to have on mumsnet so it takes a very brave person to oppose that.
I also get angry when a posters makes sweeping statements about people who voted in a certain way as though every single voter is the same. Within any section of voters there will be old and young, clever or stupid, good or bad, those that considered every angle and those who make up their mind on the day. That's what you get when the polling station opens. To say that all remainers are left leaning loonies or all Brexiteers are old and thick shows contempt for fellow human beings.
What has made the past three years seem to divide our population down the middle is social media. Its very easy to state your views, sometimes endlessly, when you have no idea of your target. In real life, we know that our friends and family and the bloke down the pub have differing views but we negotiate around it. By avoiding tricky subjects or accepting that their opposing view is their opinion and only one aspect of them, and we carry on from there. But on forums such as this, the shared background is missing and the nuances and body language cant be seen. This seems to give some posters a free rein to say some dreadful things.
So, Im sure many many gransnetters have an interest in politics but choose not to display those views for fear of a skip loads of poo falling down on them.