Earlier quoted context omitted.
Expecting CSS to solve people on holiday is not the point, but expecting a technology to protect me from the much more general problem of other developers and content generators making mistakes is something I think you can blame on CSS. Going back to brundolf's point, he's arguing that you should try and take advantage of relative constraints as much as possible as CSS lets you do that. I'm arguing the opposite, and…
CSS is not a technology designed nor intended to protect you from anything. It's a technology that enables professionals to style web pages. And it's simple enough that even amateurs can accomplish much.
Second, to call CSS simple is insane. How many ways are there to create a positioning root? How many ways to create a stacking context. How many different things can using '%' as a unit mean in different context? CSS is incredibly complex. CSS tries to shove these important concepts implicitly away from the developers notice, only to ultimately make life worse for both amatures and pros.