Maybe.

But you cannot PoC most hardware and driver related bugs without lots of time and money. Race conditions are very hard to PoC, especially if you need the PoC to actually work on more than one machine.

So while a PoC exploit does mean that a bug is worthy of a CVE, the opposite isn't true. One would overlook tons of security problems just because the discoverer of them wasn't able to get a PoC working. But it could be worth it, to maybe also keep the slop out.