I just don't understand who these changes are for? There seems to be this vocal minority of people whining about the stuff locked behind this time-gate. So what? There's plenty of people who have earned the rewards already, it's not like any of them are necessary either. They're bonuses. It never kept me awake at night that I didn't have the Sigma and Octantis. I just played the game, ground my stuff, earned my mastery and got a prize once in a while.
Why change the system? Log in rewards benefit the people who have logged in the most, it's implicit! I do not see the issue here. All I can see is people getting angry they can't get a shiny thing, these are the only items in game you can't drop plat on. Everything else in this game you work for, you grind it, you craft it, you wait. Is the issue that the time-scale is too long? If that's the case just squash the milestones down, give everybody the rewards retroactively (i.e. if you've played 1000 days you earn earn everything up to that milestone) and move on.
Don't even get me started on a choice of Prime Mods, none of the older players got to choose, that doesn't seem right.