There are two main counterarguments I have heard to casino gambling; the negative impact a Saipan casino would have on the Tinian Dynasty, and the moralizing argument that there will be more local gambling addiction. Neither of these arguments is convincing.
The CNMI has gambling already via the Tinian Dynasty, and I'm sure Tinian folks fear a Saipan casino might take away from their fragile economy. The fact that the casino is in Tinian and not Saipan, the main tourist destination, is puzzling at best. Tinian and the Dynasty is hardly a resort location with the amenities typical to such a location. There aren't many restaurants or other entertainment options there, and it is somewhat difficult to get to. I can't imagine many people come to the Marianas expressly to gamble at the Tinian Dynasty, but they very well could and would come for a focused marketing campaign based on golf, diving and gambling. It helps to have something to do at night.
I can understand the concern of Tinian folks, but it is misdirected. A casino would draw more tourists to the Mariana Islands. It is not uncommon for people to visit more than one casino, so it doesn't seem unreasonable that a Saipan casino would bring more, not less, visitors to Tinian and the Tinian Dynasty. Beyond that, what is to stop Guam from establishing a casino that would be a "drag" on Tinian by the same logic? This region is unlikely to replace Macau as the gaming destination of Asia, but people like casinos and another tourist lure is hardly a bad thing. A rising tide lifts all boats and holding back competition is never a path to success.
The second counterargument is even worse, the moralizing argument, the idea we'll all become a bunch of degenerate gamblers. My understanding is that certain influential clergy members discouraged casino gambling when this issue came up previously, and that is the reason we don't have gaming to date. This isn't Rick's Cafe in Casablanca, and it isn't shocking. Gambling exists in the open in Saipan and it largely takes place in the dark, dingy poker rooms that lack the dignity of a Bangkok sex show, so the moralizing argument is absurd given that gambling in these poker rooms is the type that has wrecked more homes than Angelina Jolie.
No cash rich, high rolling tourist is ever going to be walking into any of these poker rooms that have all the charm of a trauma ward in Darfur and start plunking down their hard earned cash needed to infuse this dead economy. Casino resorts are a place for shows, restaurants, lights and "over the top" Vegas glitz. They need that type of atmosphere or they revert to the dark, seedy, scarcely populated, smoky hellish pits we have now that attract the wrong type of gamblers -- those who least can afford it.
I came to know this island as a tourist. Given a lot of time, I would probably have gone to a place like Koh Samui, Boracay or Bali -- cheaper and more exotic. Not all vacations are long -- especially if you work in a country with long hours and short vacations like Seoul or Tokyo. To get to those places requires a flight to Bangkok or Manila and then a connecting flight to your resort. A connection going in and out is ridiculous on a short trip, which is why I came here and why a lot of people come here, at least until the lack of flights made it so difficult. This place needs to aim for the shorter term tourists who want to be on the golf course or on the beach immediately, not waiting in a terminal annoyed after ten shoe checks and parched because of the insidious threat of water. Seoul and Tokyo don't have the gorgeous golf courses, beaches or diving we have, and the casinos in Seoul don't allow Korean citizens. It is a "foreigner" only activity over there, which makes sense. Naturally we do the opposite, offer the vile poker rooms for our majority impoverished population that prey on the desperate and financially unstable.