I will probably never understand because I have never understood, and upon learning more of the church's history on this matter it left such a bad taste in my mouth I quickly gave up on my LDS apologism. So I think it's fair to say I will probably never understand.It's hard to "understand" when your intent, or approach is to find fault or scoff and scorn.
And for a creator that is omnipotent and omniscient, why change anything you do or think? What is right and what isn't can't change and there would be no incentive to change it. Whether that's instituting a ban on bestowing the priesthood based purely on racial criteria, or whether that's reversing it.
I am an atheist if that wasn't already known. May more negative rep flow my way.