As a tourist from the UK, we have many crappy Six Flag type parks local to us with crappy fast A - B roller coasters, no theming, branded something ridiculous like 'Batman rollercoaster' and painted black.
Millions of tourists flock to Orlando from all over the world for something more immersive, cutting edge attractions. They don't go for Six Flag attractions - because if the market was that huge for Six Flag-esq cheap coasters then they'd be challenging Disney and Universal - there's a reason why they get low visitors.