The point of the empire pop penalty balance seems to be you have three choices come the mid-game: Conquest, Co-operation or Stagnation. You need to find external sources of pops or resources, rather than sitting in your corner and breeding pops. You can't just ignore the rest of the galaxy and expect to thrive.
This is what it ended up becoming but I don't
think that was intentional. Making determined assimilators AAA tier while demoting fanatic pacifists to F tier probably wasn't deliberate, even if those determined assimilators were already very good and fanatic pacifists were arguably bad before. That said, I always liked to play turtling / inward perfectionist empires, so this essentially nerfed the way I liked to play the game very heavily. I can just play egalitarian federation builders until they change the system again, I guess.
In short, I think the change is overall a good one but it does require you to completely relearn how to play with the new pop system. Old strategies simply will not work, and I think that there is a bit of people:
a) Trying the old ways of growth and being annoyed they don't work.
b) Being off-put by the AI doing a better job of keeping up with the player, making people feel like they're doing relatively worse than they actually are.
I will say that after playing more, I realize the problem isn't the massive burning dumpster fire I thought it was, and is instead only a moderately large dumpster fire.
I've
definitely had to relearn pop growth and job mechanics, and after doing so I'm less upset. Seeing the little red unemployment icon is no longer the giant red flag it used to be, since those pops will move to a planet with jobs and space now. In theory it lets new colonies grow by absorbing pops from other planets.
However, it still feels pretty bad with the tuning right now. I'd
prefer to be able to continue to build up all of my planets and take advantage of their resources instead of using them as pop breeders for new colonies. And with the current tuning, ecumenopoleis and ring worlds are pretty terrible with this system. I have one ecumenopolis that I restored from a relic world that has 54 pops after 50 years or so, and a ring world segment that has 10 after 20 or so years.
And let's not forget that robot assembly plants are arguably actively detrimental after mid game, since they tie up a pop working the job and eat alloys every month. Right now it literally takes my empire over 10 years to make a robot pop for each planet, so the alloy cost to produce them has gotten kind of hilariously out of whack.
So, bets on the next DLC? I'm betting something to do with Primitive Civilizations. They're due a rework, and the current Enlightenment/Infiltration was already a proto-Archeology system so I can see it being updated to use that instead.
DLC focused around primitives could be pretty cool and I wouldn't mind it. I'll jump on the bandwagon from Paradox's forums and ask for internal politics again though. I'd really like to see mechanics for managing internal stability as a way to avoid blobbing instead of the somewhat hamfisted approaches they've used so far.