It would be interesting to know if there is a "typical" unbalanced aquarium...
It would also be interesting to know if overstocking is the "typical" part of the equation. My money is here....
Blame seems a funny card to play. If we buy a 100 gallon tank and stock it with an ideal 100 gallons of fish, but then we filter the tank with nothing but a whisper 10 filter, do we blame the whisper 10 for the ensuing issues?
If anyone bought into the "magic" of
any filtration method, they might be very likely to have problems. You can exceed the capacity of and/or misuse any system. Especially if you thought it was like magic and didn't really understand it.

Like blaming "burnt tips" on the coral growing too fast rather than blaming the carbon dosing. (We know we're messing with the tank's carbon cycle, right? I mean that's the object. But we have generally neglected the fact that corals are utterly plugged into that cycle.)
It's worthwhile putting the Berlin Method in its context too....people were running "hi tech" reefs with bio-balls, denitrators, ozone, etc, etc, etc, with controllers for each component. There were some good ones, but it was a circus, sort of like today's tanks in several ways.
Then along comes this group of reefers that have tanks running this "berlin method" that are superior to any of the "hi tech" tanks, and without the accompanying circus of controllers, etc.
They weren't promoting algae farms. They were promoting functional, balanced tanks.
The point proven was that we don't need that stuff to have a reef. (We still don't.)
We
choose that stuff because we often choose very firmly (if not conscientiously) to overstock our systems relative to the system's inherent capabilities. We rarely move slowly enough to
even know our system's inherent capabilities.
The modern response to the berlin method is "so what, we like more fish". Plus GFO and carbon dosing and pellet reactors and turf scrubbers, etc, etc, etc, etc, are all really cool. It seems like most folks start off carbon dosing, with a pellet reactor and bacterial treatments, GFO running with activated carbon and Purigen support, along with filter socks and... None of it seems to rescue them from showing up in the "Help!" threads when they've predictably overstocked their tanks.
Berlin was not enough (even though it works), GFO and phosgard wasn't enough, and now carbon dosing is not enough for what seems like most folks.
When the typical goal shifts to
achieving a balanced system – which there have been examples of all along the history of the hobby – rather than "
how many can I fit, how quick?" I think we'll collectively turn the corner on most of the major issues that plague the hobby.