I would suggest the tanks fail for a myriad of reasons and certainly not because you chose not to kneel at the alter of amano, normally poor husbandry ailed with too much light or some other element that must be at play, that and most people don't have a small army of people meticulously manicuring their tanks daily either, do they?!
The "proof" you provide is sadly purely anecdotal, you're buying into their patter, if a product does nothing detrimental then it's presence will not inhibit a good show, correct? You simply can't say "because they used this it must work" That's not how these things work, if we can prove it does nothing then it doesn't belong there and it's presence meaning a success can simply be ruled out, it's that simple. If the product was small ceramic horses would you buy into it then?! The systems you idolize and have rolled out as proof are simply not comparable systems in the way we run our tanks because they have a regime that we do not adhere to as a general rule, identical, sucessful systems exist without amanos magic dust, how do they work if you need to spend on a mineral that's cations aren't even able to release in water nor posses any benefit to the plants?
You also simply can't say "well x product wasn't present that's why you failed", that's as poor a statement to make too, because it's absence means nothing if it does nothing, the failure of the system therefore must be some other element because it can be isolated as not having any role within the system nor with it's downfall.
If it's as simply as pointing at a system and saying it works because x is present then I'm going to start selling my own snake oil ceramic horses for people to needlessly shell out on and claim that they're vital, it costs nothing to question why you're really doing something.