Edmon: "The "game" however, is either Ironman or Multiplayer (which effectively is Ironman) with no mods."
What type of multiplayer is the "correct" one? because I imagine 3-4 players goofing around playing as the same nation is a vastly different game experience than the same people playing a nation each. But the game allows you to do this, yet I don't think this is what you mean.
and
"It's very simple to understand.
1) This game has a lose condition, it's lose all your provinces.
2) Coring cost reductions help you get provinces, money, power and position faster than anything else possibly can. In this manner, this one single idea is extremely powered.
3) The game ends when you get to 1821, you get a victory screen and a score. The goal of this game, therefore, is to make it to 1821 with the highest possible score. A bit like an old arcade game really.
4) Your score is better (thus your performance is measured) typically, when you just kill everyone so you have no competitors. The faster you pull it off, the better. However, there are different nations to play, so there is depth in "Victory + Score as X nation"."
Are you by any chance a "hardcore", or "pro", First-person shooter player(Counter-strike or CoD) or League of Legends player?
because all of this reads as if you're judging and open sandbox game, with no win condition except for what you setup yourself, through the lenses of someone whos only familiarity with video games is win/lose numbers, headshots and being on top of the scoreboard.
Doktorstick:
"For me, I don't sit down to EU4 and think, "Man, I'm going to have some FUN!" It's more about the next thing to learn, the next obstacle to overcome, to more effectively crush my enemies, to see them driven before me, and to hear the lamentations of their women."
This sounds like fun to me though

I know what you're getting at but fun is very subjective(I've used "enjoyment" instead because of that). My train of thought is usually "Man, I'm going to have some FUN! dividing France into manageable pieces. Now how am I going to do that". Thus my fun/enjoyment comes from trying to split up France. And this is where I need to use my problemsolving skills and overcome various obstacles. Fun and learning/critical thinking is not mutually exclusive.
What people are criticizing the OP for is his complete inability to acknowledge other peoples enjoyment of the game as having equal value. By arrogantly assuming only he plays it "correctly" through his arbitrary standards* he pisses off a lot of people(maybe intentional). This just becomes even more annoying when the reason he is posting in the first place is because he suddenly finds the game harder, now that he can't disable various expansions
Thus he starts a thread whining about the increased difficulty through expansions, while at the same time bashing everyone who doesn't play his way as unenlightened drones/noobs. He claims Ironman is the "correct" way of playing the game because that is the only way of getting internet medals, now he's also claiming that the only real way of playing the game is to reach the year 1821 with the biggest score. Completely disregarding the fact that EU4 is intentionally set up as a large sandbox game with the goal of doing what you want, how you want aka you choose your own goals.
*So much of his argument is built on the assumption achievements have inherent value that it could be a good case study on "pro gamer" culture and achievements in itself - actually I've might just found the topic for my masters thesis