reality
Very few have the time and resources to run a test environment that replicates everything in production.
Many don't have any resources for testing unless it's code their company has created or commissioned.
Sure, you don't deploy to every box at once and you start with the most trivial but those aren't going to be DC's and HyperV hosts so you'd not find the issue in a low pain fashion.
We expect for the sums of money that we are paying to MS that they do a reasonable degree of testing.
In this case, it's clear they didn't. The scenarios that seem to result in the patch's breaking fundamental windows components are not rare edge cases.
Biting the hand that feeds IT
