They look dreadful on me too. I've always been busty with a small waist - more proportionally than actually through most of my life
, and I'm always being told that wrap tops will look great on me but they really don't. I've seen big busted women that did look good in them but I think you need the combination of height and a long waisted torso for them to work well with a big bust. The blogger in UR's post had good posture but seemed just too short waisted so her bust looked very heavy in this style and the skirt looked like it was flaring out from a point too near the bust.
I'm now just 5'3", used to be well over 5'4" and although I've lost lots of weight I do still have a biggish bust so it's not a style I plan to make for me, ever.