The reasoning does not seem that convincing. I also don't create new instances from the Manager but instead use the normal constructor like this:

instance = models.MyModel(...)
# instead of something like
models.objects.create(...)

So I would want alternative constructors in the same place...

Feel like the post's explanation for why was a little lacking. But I don't think I was going to use class methods on my models anyway, so that works out.