"Crashing Snap!" is a slight exaggeration. (The examples run forever, but they're stoppable, and other scripts can continue to run.) But yes, it's not desirable behavior.
I was using the THIS SCRIPT block in a project, and the more I left it alone (I didn't notice yet) the laggier snap! got and it became harder and harder to press the stop sign (was not registering the input because of lag). But why does it not error REPORTER DID NOT REPORT, if the reporter doesn't report?
In general, we aren't as aggressive about reporting errors as we might be, because the tests for the errors would slow down correct programs too.