I think that I pretty much have to agree with Kofi Oron's post on the 1st page of the thread. If AJ Styles wrestled in the WWE, if he had that sort of major platform to work with, then I have little doubt that he'd be a huge star in wrestling today.
The WWE is the biggest company in the world, they're synonomous with professional wrestling in the minds of most American fans and many fans around the world. The WWE is a huge machine that's able to pump out wrestling stars known across the world. Generally speaking, Styles has done the best the he can possibly do given the platform that he has to work with. People still see AJ Styles as the face of TNA and rightly so. He's the most beloved "homegrown" star in the history of TNA and he'll always have that no matter what.
The problem isn't Styles, it's the fact that he's in TNA that has mostly to do with him not a "big star" in the same sense as an Edge or Rey Mysterio or John Cena or others. TNA isn't on the same level as the WWE in terms of audience size and sheer overall notoriety and that's not really something that you can blame AJ Styles for. TNA has literally brought in some of the biggest names in professional wrestling history to take the company to the "next level" and it hasn't happened. Compared to the likes of Sting, Kurt Angle, Kevin Nash, Eric Bischoff, Ric Flair, Hulk Hogan and many others; AJ Styles is a "nobody' comparatively speaking in terms of star power.
Will AJ Styles be the sort of "star" that most think he should be or deserves to be? That's hard to say but if I were to hazard a guess, I'd probably say no because Styles will still be in TNA for many more years to come. If it does take many more years for TNA tor each that "next level", Styles probably won't be the one that ultimately takes TNA there. He'll be looked at as a TNA legend, someone that's paved the way for others but he won't be the "Hulk Hogan" or "John Cena" of TNA Wrestling if the company grows to a size at least somewhat comparable to the WWE.