It just happened that a member wanted to edit a poll option he had just added to a poll (due to a spelling mistake). I informed him that only myself, as web site administrator, could do so. However, I do plan to eventually allow any regular member to edit poll options, as long as the proper moderation tools and community supervision tools are in place.
So, this is a planned feature, although I don't know when I'll have time to implement it.
You can use this thread to discuss how you envision the workflow for adding, moderating and editing minguo poll options.