I would trust a build coming from the upstream project more than individual build efforts by people outside the upstream. It usually make it more more organized and do help people who wants a quick trial ( I wouldn't like having to build each thing I want to try). Also people keeping up with updates is a problem when you provide the builds. Imagine having to keep up with manually build 20 software/packages every couple of weeks.
Yes, we know it is mot requirement. But it is nice and convention to do.