This is only done for Shihans. It is a sign of respect and is an honor to be the person folding the hakama for him or her.
Certainly, in some groups, this is only done for Shihan.
There is one group in my immediate geographical area that I have observed on multiple occasions in which senior kyu ranked students are apparently expected to fold hakama for yudansha, and to regard the act as "a sign of respect and....an honor."
With regard for Shihan, Visiting Instructors, and the like, it has always seemed to me that there are always half-a-dozen people or more hoping to ask a question or express their thanks for the class, and the point is to free up the Shihan/Visiting Instructor/What-Have-You to deal with that as expeditiously as possible.
Reinforcement of social distinctions through provision of personal services is not a value we particularly need to import. At least, that's my view. YMMV.