It's not that there was anything inherently wrong with the off-topic stuff, they just couldn't afford the overhead of maintaining it and -- and this is the part that's still unsaid -- of defending it.

Typical problem of flexible software is that the more you're able to do with it, the more you have to do with it. When you can't scale up the manpower any more, you either limit posting or limit flexibility. That's pretty much your only options.