Creampuff, I have a radar screen which doesn't happen to include indications of cloud so I can't tell from looking at the picture if you're in severe CAVOK or about to pop out of a white fluffy thing and get a windscreen full of the VFR I'm giving you traffic on after he suddenly turns towards you unannounced. I've given traffic plenty of times on VFRs who are only a few hundred feet below a descending IFR and the response is "we're in cloud". When they pop out they'd likely be bloody close - sure they'd probably miss by random scatter but that's the only reason. Chieftain popping out on top of a 172? Great for unalerted see and avoid.
What's half a mile? Might look a long way but takes very little time to travel that distance at even 120kts. Look down, fiddle with the radio, look up and your half mile is gone.