How test Microsoft, Androind.... and Joomla core developers ? on people, blue screen of dead - sounds similiar? No exuse, just fact.
something else are demo sites, and totally different are live sites with tons of extensions, settings, custom code etc.
I agree with you, but ... sorry but i don't know what else to add.
As my colleagues say: "The more extensive the product, the more surprises. That's why I always wait 2-3 days after offcial Joomla or extension update." - sounds logical, doesn't it.