Hacker news is a news aggregation medium for "Hacker News." The purpose of this site is to get your fix of tech news that you can't get other places. It isn't burying your head in the sand to ONLY have "Hacker" news on your Hacker News site. It's sticking your head in the sand not to read any other news sources. That is on the individual. It is not the job of Hacker News to educate you on politics. The responsibility of getting good news is on the user not the medium. HN doesn't claim to be a one stop shop for all of your news.
More importantly, this is an experiment, on a site that is very interested in Science and Programming. It completely makes sense to have an experiment like this to see if it affects the quality of the comments. Being against this experiment is like my dad trying to tell me that God Created the earth 5000 years ago from parts of other planets (complete hyperbole). WTH? It doesn't matter it's one week and then it's over.
I'm assuming a good experiment will THEN make assertions and consult with the community to see if this worked, was bad/good/etc. At that point voice your concerns, but not yet, there is no evidence it's all conjecture.
Banning politics on HN is not what they are proposing, they are proposing a cease fire on HN. That is by no means a bad idea.
If they propose banning news on HN permanently I'll get out my pitchfork too (assuming the experiment goes poorly). But lets put them away for a week, then talk.