There's plenty of other boards on 4chan where you can find people from all viewpoints posting. /cgl/ is well known to be majority female, and posters on /lit/ usually express center or left viewpoints. Even on /pol/, within a thread there will often be dissenters from the normal far-right average poster. Compared to other sites like Reddit where communities and posters with certain viewpoints are straight up banned, it's a breath of fresh air.
The fact that posters have to engage with a contradictory post instead of just downvoting it as on reddit has always been the strongest suit of 4chan. It's a great foil to the tiresome hivemind-eyness and tendency for only 'approved' opinions to be allowed to flourish on reddit.