Why has Ellanse not been FDA approved yet when it's used widely in Asia and Europe?

The FDA has the strictest approval criteria in the world. Safety and efficacy are the two lodestars. Ellanse has gotten mixed reviews, based possibly on injector technique. Given that non-physicians make up an enormous segment of the injector population, the regulators must have concern. The manufacturers, on the other hand, are constantly bringing and marketing new products to public attention. There are so many fillers currently available that I would not fall into the hype.

FDA approval is a long, complex, expensive and time consuming process.
I've asked the company the same question
Their reply was: Their business is doing great in Europe/Asia and they don't see the need to enter the US market currently as they are at capacity
Maybe that's just a diplomatic business reply we will never know