I've had the same issue. I've even gone as far as filling up one quarter of my city with the low end casinos but with the lounge. So I should be attracting something in the ball park of 14 low end casinos x 4 lounges each x 1080 medium tourist attraction = 60,480 total medium wealth tourists attracted. How many I actually attract; ZERO.
Also, I failed to mention, I had low wealth tourists coming out of the wood works. I understand that bus terminals and train stations are for low and medium wealth tourists, but when they start comming out of the ferry terminal too, that's just messed up. According to the guide, ferry terminals are purely for medium and high wealth tourists. I haven't tried it yet but I'm getting the feeling that low wealth would be coming out of the airport too.
Fix your broken @$$ game; it's been a reasonable amount of time and still not even something as simple as one way roads? Com'on EA. Really sticking to your guns, "Hit 'um where it hurts; in the wallet."