I think it's just SMent legal thingies if you put it nicely (money minded if you put it ugly). Business is business though. Jessica's line would do well obviously, SMent of course would want part of it (maybe too huge of a part) by saying she is part of GG and she is indirectly using GG's name to promote her own brand. Which somewhat is true.

Personally I don't think GG members would voice out much if they are as mature I think they are. If Jessica's line does well, it benefits GG. Vice versa. Cause it's publicity. Publicity = money. Just like the others writing songs, acting, variety shows etc etc = publicity = money. More over they could be her model, pitch in some ideas, co-line some fashion lines and etc. There is so much possibilities and benefits. They'd be more supportive than against.

SMent worrying that she'd focus more on her fashion line however should be the main issue. Of course the fashion line just started. Juggling between things would be hard but not impossible.

My conclusion: I think its just SMent wanting more profit from one of their long-term profitable group. Pushed too much and things turns ugly.

Face it. They could have stopped her when she say she wants to venture into fashion line business. Why now? Why not then? Because it launched and response is way better than they imagined. SMent is a company after all.

SM wanted the piece of pie n eat it for themselves. Simply put. I believe in ot9. The drama isn't over just yet

Jessica didn't want out this early, and by the looks of it, she didn't want out permanently either. I agree that something is off here, I mean Sulli is allowed a 2 year hiatus to date, the other girls can pursue side careers, but I guess that comes down to the fact that Sica was apparently taking too much time with Blanc, and that the girls were afraid she was putting it ahead of them on her priority list.
I know she once said that when it ended, she wanted it to the be the most beautiful ending. I don't think this is what she had in mind at all.