Two transporter beams, a weirdly reflective at.osphere that only exists in a single planet in the known universe, and plot devises intended for the sole purpose of that one story.
Most of which are explained in that same episode if you'd actually pay attention to it.
The ethics of it are dubious because every time you see someone transport they are being literally killed in front of your eyes and a new copy created elsewhere.
They "nuh-uh'd" this in Enterprise. The inventor of the technology is introduced and basically says the people who propagate that theory are a constant thorn in his side, despite having no basis for it in the reality of that universe.
They also show people experiencing, and reacting to other things in, the matter streams during longer transports. Kind of hard to do if you're dead.
Well, considering much, if not most, of Star Trek takes place outside the Federation... no, not everyone is living in a post scarcity society. And slavery does exist. They just approach it from an analytical point of view, rather than an adventurous one.
This has been a joke since before anything resembling the modern "AI" boom. Basically since murderous future AI was a think in popular media, at least since Terminator if not earlier. People would joke about treating their appliances kindly so that "Skynet" won't kill them in the future.
Yes, because we haven't been calling them fools for years, maybe we should try it! Maybe it'll work and not just drive them further and further away from sanity out of spite!
Playing by someone else's rules means they dictate the conversation. You have significantly less power. If you want people to act like adults, like reasonable people, try treating them that way.
It may not work, but it's far more likely to do so than constantly talking down to them.
I mean, it wouldn't have fallen on deaf ears to those it kept happening to, just not in the US.