Hey my dudes, I do SEGA stuff and basically...
Not enough people. The way SEGA is laid out at the time really doesn't have the people to run and manage the game. This isn't even getting started on the license issues, which itself are a nightmare.
SEGA America just doesn't exist. After they acquired Atlus, SEGA America was basically shut down and basically streamlined with Atlus USA. Right now SEGA America is Atlus USA (for the most part, at least
thats how the workers paint it). SEGA Europe is its own branch and basically does PC stuff. Anything related to PC gaming, is through them. Stuff like Valkyria Chronicles on PC? Them. Total War? Them. They make more money than SEGA Japan and are highly successful. Could they bring it over? Probably the best bet but considering that they are so far behind content, when it wasn't approved back in 2011 (or was it 12?) it basically signed their death sentence. It also didn't help that SEGA Japan signed a exclusive 'English' contract with some South East Asian company that never updated it then killed the game in that region.
Some higher up at SEGA America didn't think PSO2 was worth the headache, even after they announced it. Like I said tho, those people are gone for the most part.
SEGA America aka Atlus USA is working hard on rebuilding their brand by bringing Japanese things. But they are still too small to do something that needs a big dedicated team. Personally think maybe in when the next game comes out it could.
While it does suck, the game has been playable and translated by fans for years...
Personally hoping SEGA announces localization for Yakuza Kiwami 2, Border Break, Fist of the North Star. I already played a ton of PSO2.