My opinion is based on what you initially said, which was, in a nutshell, "I choose to be ignorant of why something happens, yet I know why it happens, and this is because I'm taking my information from an unrelated place."
Now you've doubled down on parts two and three. Interesting choice.
Here are things you really don't know:
1. The name of more than one voluntarily delisted providers who are still active
2. Why any of them delisted
3. Whether or not they are distinguishable from an unreviewed provider
Whereas I know:
1. Intimately, four providers who have either de-listed or were never reviewed by choice
2. Why they chose not to be listed
3. How they compare to the Backpage providers I've been with (because the only unreviewed providers I've been with are from this very group)
As Donald Rumsfeld once said, it's what you don't know that you don't know that's the most dangerous thing. Your opinion of de-listed providers is in that zone, because you're missing out on some really good providers.