SWTOR's fault stems from its relatively lackluster quality. Their design is mostly tried and true to the WoW formula, but it lacks the immense polish of World of Warcraft; particularly with its combat system. It's also one of the most linear MMOs I can remember, which was its most off-putting feature to me during beta. Players do like some structure, but they also want freedom.

SWTOR also suffered from boring storylines. The stories were trite and only furthered classical Star Wars stereotypes. The voice acting was great, but it lacks the presentation Bioware emphasized as they tried to hide gameplay through cinematic presentation for years.

It simply isn't a matter of "casual vs old style," as you try to argue. It would be a mistake to go back to the "FFXI" design philosophy.

I would also caution against calling it a failure. If SW sold 3 million copies at $50 each.. then that's 150 million dollars. Anything on top of that is their profit. It might be best to phrase it as not living up to its Warcraft-level expectations.