Gambling is not wrong, however if gambling becomes an addiction and hurts you or the people around you, it is wrong.
I think it is completely wrong because after starting slowly most of them will be addicted to this and will loose money in the end. So just avoid it if possible.
If you have no self respect and self control, that is true. Gambling should be fun and you should gamble what you can effort. If you cannot manage that, YOU SHOULD NEVER GAMBLE.
Think before writing something on public forum. I agree on self control but why you bring in self respect? You gamble more then you will lose that.