I can go to any fide rated tournament as a unrated and play in it and my first rating will be 1900 elo and maybe higher . Why? Because I know that tactics and endgame skills will contribute to my success, I can play third rate moves in the opeing and get a playable position and outplay them in the middle game or endgame.
Malarkey. In fact, I would bet money that you wouldn't break 1900 FIDE after your first 10 rated games.
In fact, you have a FIDE membership card. Why not try out your theory and let us know how you do. I'll wait. Well, I'll wait a few months.
I should be clear: I agree that studying openings isn't very important below about 1800 strength, and becomes very important only above ~2300 strength. But yureesystem places too much faith on his skills as a player from 20 years ago. If he were to try FIDE for the first time when he was 20 years younger, I'd agree with him.
The OP didn't say that the openings are meaningless. If you study tactics, you will find that tactics occur in the opening. You don't need to study opening theory to win in the opening, study tactics!
Here's an example from a game I played today. I was out of opening theory by about move 4. I'm sure there are games that have followed this path before, but that has nothing to do with theory and everything to do with tactics.
I played 1800 fide and 2150 fide and very confident I can beat them; one 2060 fide I played, he won as white and took me to the endgame and I beat him and didn't go beyond thirty moves. If I can crush a 2060 fide I am sure I beat below 2000 fide, BTW I noticed 1800 to 1999 are sloppy calculators and give me enough time I beat any amateur or worse draw. I want to play Europeans to earn my fide rating not in America. DeirdreSkye keep repeating meaningless comments how the endgame must be study first; I know this strong expert 2160 uscf who inept in the endgame but his tactics and attack is unbelievable strong; I come to the conclusion attack abilities and tactics are more important than any area of the game. This expert who was 2160 drop to 2125 something and still is incredible strong while my other friend and I are low 2000 uscf and we play the endgame better but my friend who is 2125 uscf is an attacker. I decided I needed to change my safe positional style to more aggressive style, my reward is shorter game and more wins. Playing against experts and masters one must be strong in tactics, attacking ability, need to be a good calculator and good endgame skills; your chances to beat a master increases with those skills I mention. A master fide or uscf below 2400 is not proficient in the opening and if play according to opening principles you should get a playable game and you better be very good in tactics to survive his tactical tricks.
... He also said that if he hadn't done the mistake to overstimate openings and spend too much time in them , ...
Not the same as advocating attempted improvement "without ever studying openings".
"It is important for club players to build up a suitable opening repertoire." - GM Artur Yusupov (2010)