I think you have a vast overestimation of what is actually REQUIRED in order to get a Deep certification card. Have you read the course standards for that? From any agency? The actual standards for the SDI Deep specialty are in a PDF that is linked at the bottom of this page:
SDI Deep Diver Course - SDI | TDI | ERDI | PFI
Like I said earlier, just because a person has a card for it does not assure me of pretty much anything, regarding their proficiency as a diver or qualification to dive to 119 feet. If I know the instructor they had, then I MIGHT infer something from their card. Otherwise, as far as I know, they could have gotten their Advanced card by doing a very quick bounce to 61' in a quarry somewhere. Or their Deep card after a quick bounce to 95' in a quarry. I use those examples because I know of numerous people who got those cards in that way.
Where did I ever say that? Please provide a quote.
"It's a good idea to not get certified before you go deep diving." Nope. Never said that.
What I said was that taking a 1 day class and doing 2 dives (where absolutely minimal skills are required) with an instructor is one approach. But, I think there are other ways to learn to safely dive deeper than 60' that don't require taking a formal class. So, I would not AUTOMATICALLY assume that a person who does not have an Advanced or a Deep card is unqualified. My dad does not have a single C card of any type. But, his Chief had him doing dives to 200', when he was in the Navy. You reckon he is unqualified to dive deeper than 60' because he doesn't have an Advanced or a Deep card?