I guess the only thing I can say to that is you should check out the stuff made by Team ICO, their games are univerally praised despite being incredibly minimalistic and restraining. Though it should be noted that their design philosophy actually improve their game, it's a philosophy called design by subtraction. That giving players options is always a good thing is not true, it's highly situational and it all comes down to what you want to say and how you want your players to react to the box you put them into, the more cleverly you design a game, the more the size of that box cease to be relevant, what matters is the posibility space given. So no, there's no objective truth to game design, at least not as long as we as human beings set the precedence for what should be considered objective, because all our impressions are subjective.
"...The new system pretty much seems to encourage..."
No, it encourage *you* to do all those things. This is what you need to understand El, this is the way *you* force yourself to play the game because it's not designed the way you want. Most players do explore the maps, do quests and pick up loot, the difference is that they do it in accordance to the rules. You want to sidestep the rules and thus you get punished and you feel unfairly treated. It's about your response to the rules, not the rules themselves. You don't want to take responsibility over your reactions and want to blame everything else for being unfair, badly designed or objectively flawed. You need to pull yourself up by the bootstraps and realize that you are having a problem with the system, the system is not the problem.
No, it's not just as easy as "just putting it back". Unless you want something untested, unbalanced and subpar. Remember that a lot of balancing has been made since the change, and without the previous model in mind. The game is not balanced for infinite inventory and unrestricted trading. How much that imbalance is we don't know and that's why I said previously that it's futile to speculate and saying that it's just a matter of a few lines is speaking from a place of ignorance, unless you know the framework, which we don't.