The longer a game has been on the market, the cheaper the initial game "box" becomes as well as older expansions alowing new people to "try it out" correlating their increased interest to new expansions is a false market assumption.
When did the game first hit the ~10$/€ mark? It's been a while, isn't it?
While your statement holds true in general, it's not really the case with EU IV. The price of the base game has stagnated for a long time. Everyone remotely interested has had so many opportunities to check it out by now. The price of the expansions shouldn't matter much (besides, anything older than a year has been reduced multiple times by 75% as well), since I seriously doubt many would buy expansions to try out a new game.
I respectfully disagree with the game designer is "listening to the public". The average player likes expanding their country albeit slowly or quickly. (...)
Both ideas go against a great game designer's rules: Monsieur Sid Meier's:
Make sure the player is having fun, not the designer/computer. (Show me how the corruption system makes gameplay more fun for the player.) (Show me hoe the new state region rules moneydrain makes the game more fun for players) (Correlation - building things in your province gives bonuses and a sense of achievement. Makeing many countries have little or negative income early on is the exact opposite of fostering an environment where the game encourages the p;layer to have fun. The player is left fighting against new internal blockades in the game engine - corruption and regions - instead of the enemies they are supposed to have - other countries and keeping your country stable.)
While I do think corruption and states/territories need some balancing (we always need to wait for the next patch to see new mechanics starting to work, don't we?), I don't get your argument in general.
The main complaints I hear all the time about EU IV (which I, personally, can support as well) are:
1) The game is too easy.
2) Nothing to do except expansion.
3) Hardly anyone reaches late game / finishes their campaigns most of the time.
As far as I see, the developers are constantly trying to find a solution to these problems, which is absolutely requested by a large part of the players judging from forum posts, now in the form of corruption and states/territories.
So, how is the challenge to have a stable/ affluent realm an inherently bad thing? Since EU III, money has never been an issue after a few decades into any campaign, which is somewhat unrealistic and has always been complained about (and rightly so). How is it bad that money realistically becomes another constraint besides monarch power?
How is it bad that you can't blob as easily anymore while keeping absolute control over even remote parts of your empire, which, again, is unrealistic and has been criticized many times before. It was high time for a change here, so why not try it with the increased autonomy of territories?
The new system even provides players with much more control than e.g. the flat autonomy increase of overseas provinces. Now, we can at least decide which provinces/regions we value more and like to have better integrated in our realm.
The funny thing is, if we would just play at higher game speeds a bit more, there shouldn't even be a big difference compared to before. Except, we actually would reach mid/late game and smaller nations had a chance to survive the first 50 years for once. How would that be less fun?
The one thing that
is getting harder are world conquests. But I can see balancing those with a viable mid/late game with any challenge left to be incredibly difficult in any case.
Again, this doesn't mean corruption and territories work perfectly as of right now. I do think they need balancing!
In my recent campaign, the AI has lots of problems to deal with the new economic constraints. Scotland has been in severe debts for decades following three rebellions and after they subsequently dishonored their alliance with France, they got conquered by an Irish 2PM it apparently couldn't afford to keep more than 3000 men under arms.
Because they can add artificial new game mechanices to make players poorer and slower to do what they want doesn't mean they SHOULD). Why are the way players play the game wrong? Could not the exact same result desired - slower huge blogging come about as a result of tweaking simple game mechanics (see rule 3) - lik stability hits for adding provinces, additional bad boy points for expansion, etc, etc.
The way players play the game is absolutely not wrong. However, where is the fun, when you're bigger than anyone else 50 years into the game? Shouldn't the game designer's acknowledge if the game doesn't work as intended / there are game design flaws and try to address those?
How is introducing new artificial mechanics worse than tuning / expanding existing artificial mechanics?
And - that may be personal - how on earth would getting a stability hit of all things be better? Am i the only one getting nightmare from the mere sound of it?

Next thing you propose is fixing things by introducing more increased coring cost penalties.
