These types of vlogs aren't my thing either, but they're great fan service, and most of BP's fans are women and young girls who probably love to know what their bias does with her hair/make-up.
I've said that I think that Jennie is the most "Western", and the most likely to wind up living in Los Angeles or Paris. That vlog of her day in L.A. showed how much she loved being able to just go out and walk around without all of the attention. I also think that all of the girls except Jisoo chafe under the restrictive nature of S. Korean social norms and the constant pressure of knetz analyzing everything they do. They seem to have so much more fun and be so much more relaxed when they're out of Korea.