I agree with your distinction between subjective and objective. Your points are still, largely, subjective, because you are saying the system is BAD FOR YOU. For example:
The current system breaks game immersion
This is PURELY subjective. Evidence? I find this system, SUBJECTIVELY FOR ME, increases immersion, or at least balances practicalities of game mechanics with immersion. If it OBJECTIVELY broke immersion, then it would mean it breaks game immersion for EVERYONE. It doesn't.
That is, without recourse, a subjective argument on your behalf. That is fine, but be aware that it is a subjective argument no matter how much you say otherwise.
makes the economy system utherly impossible to balance
I do not agree with this statement.
I can see some areas for improvement with the economy, and certainly after a certain point I have accumulated a large amount of money. I can also see plenty of solutions that do not involve discarding the current system. I think part of the issue here is how we define "balanced"; you want the game balanced towards one style of play, whereas I find the game, as it stands, appeals to my personal style of play. In this sense, I will argue that there is a degree of subjectivity here in your claim as well.
A traditional "vendors purchase anything and have unlimited cash" approach would be much EASIER to balance, but I'd (subjectively) find this boring, because I enjoy the current system and the (slight) strategy involved. Also, again this is an immersion issue - for me, the concept of a merchant who will buy or barter ANYTHING is unrealistic enough to break immersion FOR ME.
wastes either player time to pick up and sell everything, or wastes developer time in all the areas that are created and are not going to be used most of the time because there is no point to it.
This is not Diablo. There are reasons for entering areas other than just collecting loot. This is something of a conflict between HOW YOU PLAY THE GAME and HOW THE GAME IS DESIGNED. For one, I DON'T PICK UP AND SELL EVERYTHING, and the greatest pleasure I have found in the game has been exploration. I loot tactically and selectively. I role play a bit. I'd actually like the system made even more strict, so that greater emphasis on strategy needs to be employed while looting. (I'm probably in a minority here though.)
I break down a lot of stuff I can't carry so that it isn't an entire waste (although I really would like more breakdown options...) I use my Player Home to store components between looting runs, and typically target specific types of components (this definitely could require expansion and balancing, true, but that is not a function of the economy per se) and I have gained immense satisfaction from the game. While the crafting and economic system are far from perfect, I absolutely disagree that it is broken or immersion-destroying, and I whole-heartedly disagree that it means there is no point to visiting areas.
On the contrary, I visit those areas because they're THERE to be discovered, and this for me is truly the charm of the game.
not being able to balance the economy because of the limitation of merchants buying stuff. You can adjust prices all you want, it's not gonna make a diffence because you'll always have enough, too much or too little money no matter if you do sidequests or explore.
EVERY game economy can be gamed. As it is, I only started gaining too much cash near the end of the new content.
For most of the game, I've had more or less just enough cash for important things, have crafted some things to fill in the gaps, and when I've really wanted a big ticket item, I've gone out, explored a lot of the out-of-the-way content and looted and traded intelligently until I could afford it. (For example, there was one particular quest where I required a very substantial amount of cash. There are various ways of getting that cash. I looted abandoned places and robbed bandits for it, and rather enjoyed the experience.) This sounds to me very close to the ideal balanced economic system you described. It isn't perfect, but it is not unbalanced to any degree that can't be fixed with tweaks. I think it is absolutely workable.
It seems to me that your problem is that the current system DISINCENTIVISES loot grinding, and you want loot grinding. I loathe loot grinding (and level grinding). Subjectively speaking, I think the current system WORKS because it discourages loot grinding, without outright preventing the player from doing it if they wish (or need) to.
The very fact that I have not had the same problems as you, and in fact have almost entirely had THE OPPOSITE EXPERIENCE from you, suggests that:
1) We have very different styles of playing, and
2) The game is balanced more towards one style than another, which means
3) All of your arguments are based around YOUR STYLE OF PLAY (including your unsupported argument that the system is impossible to balance),
4) Which makes your arguments subjective.
I am sorry, but that is what subjective means. If you say "This OBJECTIVELY DOESN'T WORK AND IS IMMERSION BREAKING" and I say "But it works for me and I find it immersive" and then your statement is subjective, not objective.
Feel free to make your arguments based on how you feel the game should play, but don't try saying it is OBJECTIVELY anything when it is in fact based precisely on how you feel a game should play.
It is my personal opinion that the current system
i) is workable (and does in fact work for me rather well)
ii) is potentially enjoyable (because I actually enjoy it), and
iii) should remain in the game, although I accept
iv) it still needs tweaking.
Like your opinion, this is purely subjective, for what it is worth.