No gambling is not prohibited everywhere in the world. Most of the government provide licenses to online and traditional casinos and make good money out of it.
Still, there are many people operating casinos without getting any permission to save taxes, that can cause legal issue for players as well.
However, it is not because of this act by the government that makes it to be portrayed negative, it is just because of the fact that it brings a lot of negativity virtually to most of the people that are involved in it, probably because they had the wrong mindset which most of the time is always the case and then they get so overwhelmed until the lose out completely.