I don't think it's "star power" issue, but rather a problem related to the visual identity of the group (i'm not talking about girls visual but art visual). Their music and concept vary enormously but there is no visual identity to tie it all together and worse than that I find that aesthetically the group is very behind compared to what the industry in general offers.
Sweet Juice had managed to reach a wider audience because I think partly that although the music was very good, there was a stronger visual identity that came across in general. I find that it got lost again with "BBB" and "7Heaven" the group can't find consistency, and it seems like they are still searching for themselves artistically and that everything remains very conceptual in their aesthetics.
That's a solid point. I agree that they needed consistency and going with BBB and 7Heaven wasn't that wise of a choice. They most likely would be in a better spot if they had consistency and built on Sweet Juice style/concept. I think they got scared due to not charting well and selling that many units. Social media wise I felt they got a lot of attention with Sweet Juice, but social media engagement doesn't = $