On certain occasions, legitimate safety is a factor. Security is one area where physical strength is necessary, and most "brothers" are more likely to have that (remember, they are not allowed to carry a gun, which would even things).
That aside, this is blatant discrimination. Parking attendants, regardless of gender, should be allowed to perform on equal footing. "Sister" volunteers should not have to submit to "brothers" while doing their assignment, except if they are trainees (in which case the purpose would be for the "sister" to learn the job) or if safety and strength are issues. But there is no reason why a "sister" would have to be in submission for a simple cleaning assignment or to distribute littera-trash.
I am hoping that this causes enough of them to take the job and shove it. It doesn't matter who is holding up that sign (as if I would obey it anyway). Hopefully, there aren't enough men to go around, positions go unfilled, and the whole a$$embly degenerates into such a mess that they have to cancel the whole thing (and I am not going to even show up, let alone lift a finger for them). I am also hoping that, when such blatant discrimination against women becomes the norm, that they will all start walking out of the organization.
I wonder if it also takes a guy to handle those extra S-77 forms for delivery to the congregations for the extra disassociation letters I am hoping this generates.