

Maybe, I tend to avoid big instances and news. I also heard stuff about news.world mod so I’m not surprised about what you said.
But I believe it is one dude on one community on one instance, there are still plenty of news community outside of world, ml and (former) grad so they are easy to avoid.
And it doesn’t change the fact that free speech != spewing hate so if some are looking for that kind of freedom, well, they can look elsewhere.
As said, most probably Christian heritage. Even in secular countries like France it is forbidden.
To be precise about France, only polygamous weddings are forbidden but being polygamous without being wedded is not illegal. I think it has historically something to do with central Africa immigration from the former colonies.
You could migrate to France and ask for family reunion to have your wife and kids legally come, but I guess they wanted to put some limits so it was decided that wedding means one partner only. Those laws were made by old right wing parties so it is kind of logical that they wanted to limit African immigration to 2 adults + kids instead of 4 adults + kids.
Would it be frowned upon? Maybe, mostly by older folks and more traditional peoples but the larger part of the population would just not care. The problem is with legal status, without a wedding you can have child care and heritage problems in case of death.