The problem with this argument is a lot of language communities grow into large communities, and often have lots of discussion areas which are not central to th

The problem with this argument is a lot of language communities grow into large communities, and often have lots of discussion areas which are not central to the language topic. E.g. they may have a place to discuss video games, or other languages, or politics. Even if they don't it's not uncommon for people to chat socially during down-time. Unless you're going to outlaw all socialising, the "off-topic" approach doesn't work for large communities.