Earlier quoted context omitted.
But if they have IP considerations or trade secrets to protect, they wouldn't contribute them to any other open source project either. This way, they can at least upstream everything, which doesn't fall under these restrictions.
They don't upstream everything, while reducing their development costs, that is the point. Personally I don't care, but I bet many FOSS anti-GPL advocates will eventually care.
_ph_ meant to write "This way, they can at least upstream everything which doesn't fall under these restrictions." (note the deleted comma before "which"), i.e., they can at least upstream something instead of nothing.