This may be true for you, and I think it's unfortunate that you don't find the game to your liking anymore, but there is nothing to suggest your experience is shared by the majority of people who complained about the changes, and quite a lot to suggest that it isn't.
What precisely is it that makes the game unplayable for you now, if I may ask?
Since you are curious, let me take the liberty to answer, even though the question was not addressed to me.
Wiz, first of all, I want to tell you that I appreciate that you talk to us here. Also, I admire your courage that you put your face behind all the changes and design decisions you make (release videos etc.), no matter if I agree with them or not.
Second, among all the good stuff you bring us, the things that bother me among all these changes are those that break some features that worked fine before but then you said "Balancing" and the value of these features is suddenly so low that I do not use them in game any more. Basically, you made a decision on my behalf, removing some choices from me and fun on my part with them. Looks like change for the sake of change. Or obsession of preventing exploits.
Example 1 - Imperial Authority
A few patches back, the emperor used to get 10 IA for naming new elector. I found it fair - I do something for the empire, so I am rewarded for it. But some players used that as an exploit to revoke fast. Then so what? Though I learned this game quite well, including few exploits, I still rather enjoy playing "historically", "role-playing" by creating some alternative version of history. Using exploits does not bring me much fun, and I assume most players feel the same. Instead of IA that the player could influence with his actions in the game and feel their impact, today we have IA as some sort of time counter (with much less influence over it) causing more or less arbitrary delay for reforms. Boring - just sit and wait.
Example 2 - Locking war leaders
Before, the war leader changed according to power of involved countries. If small HRE state called for help, the all powerful emperor could answer the call and assume the leadership. If he won, sometimes incurring devastating costs in terms of manpower, money, war exhaustion etc., he could decide the spoils of war. No more! I still remember the frustration and anger when I defended 3 HRE minors in 3 simultaneous wars, almost ruined my power base in the process, who then kindly decided to let badly defeated France get away with huge fine of 35 ducats! I was furious about that. No more defending minors on my part, it is everyone for himself from now on. Again, there was this psychological link between actions in game and some reward for it that was broken here.
Example 3 - Innovative IG.
Before, including Knowledge Transfer, this IG was a relevant choice for playing tall even before patch 1.12. If you play tall, you do not make war all the time as opposed to players / AI factions who do. Your AT is naturally more scarce, and I learned it hard way how important AT is for winning battles (even in defensive war). Without it, the player is at the mercy of his allies, and that is a shaky proposition at best. Then you removed Knowledge Transfer from this IG, effectively pushing it just below the bar of being attractive enough, in competition of warmonger IG (Administrative + Religious). Then you talk about EU4 going in the direction to prefer playing tall. I do not get it.
I think I could go on for quite a while with other features where I do not get the purpose of these changes (statesman advisor, AT, claims, unique buildings, rule for picking IG category etc.). I do not mind if you make the game harder for us, especially since we learned it quite well and need tougher challenges. But I do mind if you make it harder at the expense of having fun. I am asking, because I do not understand.
Regarding patch 1.12, I think I bought on day 1 or 2 this time IIRC, tried to play several times, and then returned to previous patches for the time being. After some campaigns when I just marched my armies around Germany and Polish regions in small wars, won battles, sieges and wars, but ended without armies and manpower due to insanely high attrition, and without any AT gains to speak of. In my opinion, the overall direction is good, I like the concept of going tall over wide, just think the implementation is still half-way done. Just waiting until you get those crucial details right before I upgrade permanently.
Third, I would like to make some suggestions. I understand that you cannot provide detailed reasoning for every change you make due to sheer amount of them in each and every patch. So how about this:
A. Could you run regular Q&A sessions in this forum? Every week or month, for an hour or two, you make the choice. Players would fire questions, you reply on the fly.
B. Could you discuss the changes you plan to make BEFORE you actually make them? Some of them, maybe those essential ones? Today, you just announce them as you approach the release, which is much appreciated. But it is already late. I think you can make it to next level.
We are your customers, after all, we pay for your work. I believe this approach would be much appreciated in this community. And from marketing point of view, Paradox would make the relationship with its customers much stronger.
Yours sincerely, Z.