If the missing driver happens to be the ethernet driver, the unit will be "bricked" as well. Even a simple unrelated change in the image Makefile can brick a whole range of models - or stuff like ethernet driver register changes that work on most but a few specific hardware revs. We don't even have a physical sample of each device we support, it is impossible to test anything.
Your comment about quality checking in the development process is wishful thinking, we don't have the resources to regression test each trivial change on the full range of supported platforms. And yes, most bricking commits where trivial changes, not something big like a kernel update.
If you're unable to recover your device from a bad flash then don't use trunk snapshots. If you maintain production setups then get a local testbed and stop deploying untested images.
So please keep your possibly wrong opinion or actually try to maintain a few dozen models over the course of a few months before doing such statements. From a bystanders perspective everything seems obvious and simple, especially if looking at stuff after it has been fixed.