One simple thing that distinguishes gambling and trading is the simplicity behind gambling, anyone can decide to gamble without having the technical know how's of what to do, trading on the other hand isn't the same... just like something you said here, some people don't want to learn they just want to earn, this category of people are the ones that treat trading like gambling...one of the mistakes this type of people make is that they use signals from others to trade and because they feel like someone else is doing work for them they don't bother to gain knowledge.
Gambling is not the same as trading; that's correct, but both require the person to know what they are doing before they can be able to have a good experience. In gambling, it's not all games that you can play without knowing how to go about it.
Just like people copy trade from others online, that's also how some people depend on others for game sources to copy from them and place bets without knowing what they are doing. Both share a bit of similarities even if they are not the same.