Jiujitsu has evolved greatly in recent decades, and many moves not described by Helio and Carlos back in the day can be seen nowadays employed successfully in serious competition.
But for every fifty-fifty guard there are dozens of techniques whose names you'll never know, because they couldn't really cut it against competent fighters. In jiujitsu, what works is what works, and flawed ideas have a way of getting discarded.
So a reader perhaps had the wrong approach in mind when he asked Rickson Gracie about the best way to create new moves and techniques. The master answered like this.