You are right Ms A. whoever zeros out first wins.
I think for me, seeing others go up and down lets me be ok with the bouncing that happens, I don't feel all alone. I like to encourage those that go past the 5 lbs mark because I have been there, I also find by posting my bouncing I am being more realistic about how the process of weight loss happens for me.
As mentioned before, one can update when they want. It is an individual decision whether one does daily with their daily weight or not.