The issue, at least as I see it, that they're trying to address is a pretty common one, where the AI tries to do whatever off the cuff suggestion, takes it way too seriously, and does something clearly unhinged. This kind of grounding, I suspect, makes it pull its head out of its metaphorical hindparts, and I suspect is a big part of the change from Opus 4.7 to 4.8 - it started questioning everything, they started injecting "wait" more, that kind of thing.

Also, the ultima ratio regum is "use the codebase to do something actually useful and report on whether it works or not", all code must intersect the real world at some point, and that's the point where the slop shows up.