Having just completed my Atma weapon a second ago, I realized just why we're expected to do FATEs to get them. It's a test of desire and patience, to see which players are the most willing to take the time and effort to farm all those FATEs for the upgraded weapon, regardless of the odds. For those of us who are able to take the patience to get it, we have what it takes to max out the weapons, and have the 'honor' of being one of the few to hold them. Or something like that anyway, it was a random possible epiphany moment.