Yes, You're right. It is. Sure. It works according to UNA plans. That's why I've post it in Suggestions, not in Troubleshooting:)) 

But.

Let's open, you and me, the Close Group named, say, Smart Guys. Or Reading Shelf. Or Save the Ocean. And WE (you and me, remember?) both wants to make this group closed and very selective. let's say, that we do want IN THERE Leonid and somehow DO NOT want there Andrew. For some reason. And WE BOTH don't want to heart Andrew and we don't want him to know that we both are inventors of this group and, more than this, we do invite Leonid. 

I'm ensure you, Оpen Members List of Close Groups - is a very hard_to_menage thing.

It is best recipe for jealousy and litige in small or medium community.

With all my respect and acknowledgment :))

Yes, but nobody can find secret group. It is very inconvinient because the invitation can be sent only in email, not on site.

The main idea imho is: If in close group there is no option to hide members list - the closing itself is pointless. Members are the content of the group and it have to be such option. Finally - let admin to deside.