The post of your I replied to with the source says
> Sure, we could get into a discussion on the morality of gambling itself, but if we look at pretty much every global ethical tradition (Islam, Christianity, Hinduism, etc.) it is frowned upon strongly.
Yes, that was how it reads to me, that gambling itself is frowned on; based on the post that reply was for where they stated "I would say gambling in itself isnt immoral." and that the problem is addiction and money. And I also agree with that. But gambling is gambling and while no part of it is immoral to me (I hold higher standards for that word), there are major issues with it due to greed.
Which is what your souce is saying Christians have a problem with, not it being widespread or happening at all -- simply the trying to get rich, the addiction to money -- thats the sin. Not gambling, gambling is fine; it's when it turn into a money issue, then there is a problem. And that can happen at your local bingo parlour or Macau, or Vegas or the back-room of a gas station or your buddy's poker game. The Christian bible/church have an issue when greed happens, not gambling (widespread or not).