Meh, I don't like that explanation.
The mythos of Shazam has evolved a lot since his original 1960s debut and I think its all been for the better.
The mythos went from some old Wizard being the true source of the ancient Greek Gods power to being a Lord of Order, like Dr. Fate.
I tend to like the idea that intent has to accompany him saying his name so he doesn't fall into the same trap as other heros / anti-heroes where their own name becomes taboo; even to themselves.
Consequently, I'll toss out I really liked that short stent where they explored Aquaman's powers being related to the Lords of Order in so far that his trident is in fact a Lord of Order and gave him access to some phenomenal magic that easily surpassed Zanata's in raw power. I'm honestly sad we haven't seen this Aquaman explored in animation
yet; I think he'd be popular.