I have no issue with your opinion, just this portion of your comment, which did take on a high & mighty tone, at least to me.
A lone fish in a tank with just a flower pot for company that spends most of its time chasing your finger is not living a life anywhere near normal in my eyes.
As stated previously, a rather broad brush that you were painting with. Not all lone fish are kept alone with fingers wagging in front of them. Personally I found that to be more than just an opinion, but a rather judgemental snide comment. It's ok to share an opinion, but when it takes on an elitist tone, you've lost me pal.
Not all fish do well in the confines of a glass tank, with other fish, including females. How many times must this be repeated? lol I assumed your experience must be somewhat limited, as this shouldn't come as any real surprise to anyone that has been keeping some of these fish over the long haul.
Even the Amphilophus of the Great Lakes that you referred to, as adults have their own space in nature, beyond the juvenile stage they do not swim in schools, with some kind of social hierarchy, as seen in various other species.
The following is an excerpt from one of George Barlow's papers, who I think has probably spent more time studying these fish in nature, and captivity, than any other person in history.
Leaving aside the territorial breeding
adults, aggregated fish in the wild tolerate being close together
with little expression of aggression. They do spar
over food when working the bottom; but these outbreaks
are brief, with one fish making a quick, short charge at the
other, which generally swims away. But a few moments
later, when moving about or hovering as a close group, the
same two fish may resume the spatial proximity that prevailed
when one attacked the other. Midas cichlids behave
the same way in captivity in a spacious pool. But the fighting
in aquaria conveys an entirely different view of their
aggressiveness.
When kept in small groups, say two to seven fish, in
aquaria of 100 to 400 1 capacity, there is almost continual
fighting. This results in injury and ultimately the death of
weaker individuals. There appear to be three factors contributing
to this. First, the subordinate fish cannot move far
enough away from the attacker, as it would in nature. Second,
being confined to the same place, the fish tend to
become territorial, which often leads to breeding, and thus
they are not in the same behavioral set as schooling wild
fish. Third, in small groups the dominant fish seems to
sustain its attacks on selected individuals.
Those who have experience with many of these larger more aggro species have come to learn that firstly, ALL fish are individuals, with individual temperaments and behavioural characteristics. You cannot simply place all fish from the same genus or species in to the same nice neat little package. I once owned a large adult Aulonocara, a species most would consider relatively peaceful, that hated any/all female fish of his genus, and would kill them on sight. He was a large bull of a fish, and required to be kept with males only. I had another set up that housed several L. caeruleus, that after 2 years of being together the dominant male decided he could no longer tolerate the sub dom male, and one day killed him outright. This was in a 6ft tank, with 4" fish, that most would say are one of the most non aggro fish of the genus.
What George explained above is why sometimes one will see a tank full of large male Amphs, all seemingly getting along, where in that same size tank a single m/f pair would result with one very dead female. Having several females could result in the same fate, at least when one is speaking of adult Amphs. In nature, adult and semi adult groups of Amphs congregate around cover, and in the turbid water of the great lakes this behaviour has more than likely been adapted over time as cover can be scarce in certain parts and depths of the water. Close aggregations in open water are generally only seen in juveniles of this genus. And that doesn't equate to this same behaviour playing out the same way in home aquaria, with tank raised fish that are hundreds/ thousands of generations removed from the wild.
Using your logic one should only keep this genus in large pools to avoid this behavioural trait seen in captivity, or when one of these fish that just won't work in a group surfaces, do what exactly, put them out of their misery with a hammer to the head? My male amphs aggro personality surfaced at 3", when he was attacking and running siblings of both sexes from one end of a 6ft tank to the other. Even in a very large space, with lots of cute little rocks & branches for breaks in line of sight, he seeked out anything breathing and killed it. Not even a pleco could survive. And just for the record, this isn't a hybrid cross, this is a pure A. citrinellus.
The reality is that all of the fish kept in glass boxes are in one form or another a wet pet. If you choose to believe otherwise that's certainly your prerogative, but you're only fooling yourself.
The ironic part ehh, your midevil set up is the very type of tank that this person seems to despise.
