Why wear bib shorts?

[ehirsch83]

Wow, I've never had that happen! How would suspender straps prevent something like that anyway? Sounds counter-intuitive somehow...

I feel that most shorts, at least the ones I have tend to ride up and rub around the 30 mile mark. I tend to start welcoming red lights so I can adjust it.
The bibs tend to keep everything in one place, they keep the shorts from twisting and moving.