~snip
You might be right but in my own opinion gambling and trading are the samething because the future is not promised cause they both involve in risk taking. However, life without risk is no existence and the reason why gambling is portrayed negatively was because most people don't care to know about the depth of it before judging it and how would you understand whats inside a book by just looking at the cover?
The second reason are those that gamble immature way.
Gambling is portrayed negatively almost everywhere because you have heard the stories of addicts and their losses. These stories include how they destroyed their lives just by gambling and since then, it has been viewed as a negative thing and you cannot do anything about it. That's just how the world is now and you just have to be careful and understand what you are going to do.