Because she is making too many mistakes in her LP's. And let's not forget about SLC event, that was also an internatinal competition. You guys give her the benefit of the doubt at SC, saying she had jitters. She should have not been that nervous, after her 1 competition under the belt. Her Very good SP at COR might have been the exception, because she skated first.
The thing is though, at COR Gracie matched Christina's TEB FS score, except Gao was clean with 6 triples while Gracie made a number of mistakes and only completed 4. So I do think there is something to be said about having a strong SP skater on the team because in the end I think it can help save your scores a bit at a place like Worlds should you not skate so well in the FS. I think this has been the reason Russia has been able to get 3 ladies spots the last few years, she can skate a good SP and make the final flight, then bombs her FS but being in that final group keeps her score from dipping too low and the result was that her placements ended up high enough to get the 3rd spot.
I think Gao was a bit undermarked for her her FS in Paris but it's not that surprising considering her placement after the SP and skate order. Similarly, I think if Gracie hadn't skated last in the final group at COR, and certainly had she skated in the second group, her FS score would have been lower.
At this point, Gao seems like a stronger FS skater than Gold, however, if a mistake in her SP relegates to 52 points, it means that at Worlds, a mistake or two in the SP may put her out of even the penultimate group for the FS, and even a clean SP may only get her to the penultimate group. And if she's skating in the 2nd or 3rd warmup, my fear is that she puts out a great long like she did today and just gets an okay score b/c the judges are saving the big marks for the final flight, and as a result she doesn't move up as much. Meanwhile with Gracie's SP content, she should be able to make the final flight if clean, and with a slight miss likely at least the penultimate, and then if she flubs the FS a bit her scores will likely be decent enough to keep her overall standing relatively stable.
As for Agnes we'll have to see if she can skate another good SP at NHK. She's known for coming undone in the FS, and even at COR her nearly clean program only scored 106 and just enough for her to eek out 3rd. If she can deliver another clean 60+ SP at NHK and/or Nationals, that might give her heavy edge over Christina for the reasoning I just mentioned with Gracie, unless she goes back to completely melting down in her FS in which case even a good SP could not save her and Gao would be the better choice.
Mirai hasn't skated a clean SP yet and she can really have problems in either program, hard to tell with her. So for now she's the wildcard behind Christina and Agnes for me regarding Worlds and 4CC teams. But a strong showing and good scores at NHK could change that.