I think you are splitting hairs, and both you and Steve are correct.
If there is a 3-mile long no-passing zone of double-yellow, and there ARE signs at either end of the 3 miles, it would be illegal to pass, even if you cannot see the signs at various points in the zone. (The standard of double lines AND signs is met, even if a drive might not be able to see a sign, because they only need to be there at the beginning and end, not at points in between).
I think this is the point that Steve and someone else was trying to make, and it appears correct.
But you absolutely appear to be correct that if there is
only a double line, with no signs at the beginning and end of a zone, then the law would seem to say that it is not illegal to pass.
So in a sense I think your disagreement is because you are talking about two subtly different things, and you're not necessarily in substantial disagreement at all.