Hence, these testing issues aren't a major concern for enterprise - they know that they'll only get the update once millions of other people have received it without major issue.
Maybe, but those home users are typically doing very different things. The kinds of features that enterprises are using are not being tested at all in this model, and it shows.
MS did have a go a while back at trying to get an Insiders for Business thing going, but as far as I know there's been very little take-up of that (not surprisingly). Also, the whole insider build approach assumes you're ok with regular in-place upgrades from one build to another, and this process in itself is not well suited to enterprise use.