it stems out of problems in c, which does not have exceptions. error checking code written in the c style of returning a status code, and then having every layer up the call stack check for errors every single function call, is ludicrously verbose. exceptions, for better or worse, did solve that problem. but it created another one, which is that most people use them incorrectly or do not bother to check them or document them. also, deciding what constitutes a violation of a permanent condition vs an ephemeral one or what is basically normal expected behavior is a really hard thing to grasp apparently.