Was Nemo an evil villain?
There as a topic asking if Nemo could be considered a villain.
Of course he could be categorized as a villain, and you could probably find people who think of him as a villain.
Remember the story of Sodom and Gemorrah when Lot asked God not to destroy the cities if he could find good men in them. Lot keep asking God not to destroy the cities if Lot could find smaller and smaller numbers of good men in them, and God kept agreeeing. But in the end Lot couldn't find any good men and God destroyed the cities.
But if Lot had thought to ask God not to destroy the cities if Lot could find a hundred good children under the age of ten, or fifty good children under the age of five, or ten good children under the age of one, or something, God would have had to give up and agree not to destroy Sodom and Gemorrah. So the ghosts of Sodom and Gemorrah could say: "Thanks a lot, Lot! If you had only been smart enough to think of reminding God about the kids we'd all be alive now!"
By the late 1860s it was certainly common for womena and children to travel on passenger ships. And sometimes they did not survive shipwerecks. So anyone who deliberately sunk a passenger ship would be an evil villain who ruthlessly endangered the lives of women and children
So no ship sinker could be a good or decent person unless he only sunk ships which could not possibly have any women or teenagers or children aboard. And good luck finding any such ships in the 1860s!
There were a lots of ships which didn't have any women, or teenagers, or children aboard, but how oculd anybody tell them apart from the ships which did have some aboard merely by looking at them? All classes of ships sometimes had women, or teenagers, or children aboard.
Naval ships for example still had teenage or preteen officers and enlisteed men aboard.
During the Civil War the minimum age of enlisting in the US Navy was fourteen. And there is record of one ship's boy who enlisted at the recorded age of fourteen in 1861, 1862, 1863, 1864, and 1865. He was actually only ten the first time he enlisted.
In the Royal Navy midshipmen and boys aged 16.0 to 18.0 still served on combat ships during World War I, and I estimate about a hundred in that age range were killed at the Battle of Jutland in 1916.
And of course there were boy sailors on merchant ships. Since teenage and preteen sailors were a minority, you might think that sinking small ships with small crews would be a way to avoid risk to womena and kids.
The Brigantine Mary Celeste had a crew of just eight men who dissappeared in 1872. But the captains's wife and baby daughter also disaapeared from the ship.
The Doctor Who story "The Chase" had a scene where Dalecks chasing the Doctor materialied aboard the Mary Celeste and the terrified crew jumbed overboard, presumably to drown. I think it was in very bad tasete to take a comedic approuch to an event which presumably soon led to the drowning death of two-year-old Sophie Matilda Briggs.
What about convict ships carring convicted criminals to exile? If the passengers were all criminals the crew could still include boys and possibly the wife and children of the captain or other officers might be passengers. And criminals don't have to be all men nor all adults. If the convicts sent to Australia had all been male the population of the country would be much smaller. And children were also sentenced to be transported to Australia. I believe women and children were drwoned inthe famous sinking of a convict ship headed to Australia.
Of course It was still possible to sink ships without endangering women and children if the attacker gave the crew and passengers warning and enough time to man the lifeboats (if there were enough lifeboats for everyone) and stock them with food and water before sinking the ship, and then perhaps towed the lifeboats part way to safe harbors, or took the passengers and crew aboard his ship until they could be released in a neutral port. Some famous sea raiders in World War I and Wrold WAr II did this and avoided killing women and children or anyone else.
But Nemo pretended that the Nautelus was a giant narwhale-like sea monster and so could not hail ships and warn them that they had fifteen minutes to man the lifeboats before being sunk without blowing his disguise as a sea monster. So he sunk ships without warning and in doing so became a sea monster.
So that is why some people consider Captain Nemo to be an evil villain.