Interesting post OP, but I have to disagree. The design of DAI is far more akin to BG1. I do not feel that Bioware has gone in the wrong direction. IBioware has gone back design wise to what made BG1 successful IMHO.
Many posters were complaining about the lack of Stat point allocation. Early crpgs did not allow adding to attributes especially those based on the D & D 2,0 ruleset. The only early crpg that allowed adding to stats was one based on the T & T system called Crusaders of Khazan.
The Fallout series onlu allowed limited stat allocation in the SPECIAL system. Perks made up the bulk of changes to the character. DAI uses skills in much the same manner.
The semi open world is a throwback to BG1.
Limited healing is a throwback to BG1 and D & D. Healing was limited to potions and the few heraling spells that the cleric class had.
The rest mechanic goes back to BG1.
Bioware started deviating from the "crpg formula" with NeverWinter Nights which eliminated permadeath.
DAO added in regnerating health which is a staple of MMOs. DA2 took that concept further with complete health regen after each battle. DAI is actually bringing it back to BG1 standards.
BG1 was about damage mitigation which is proactive versus damage healing which is reactive. .
Oh, come on. It's an interesting idea, but stretched.
Adding stats is different from stats allocation. Correct me if I'm wrong, but BG1 allowed you to create any sort of character you wanted, apart from class restrictions - bard has to have at least x charisma and so forth. These restrictions however do not impair your ability to shape a character that fits your gaming need and strikes you fancy, i.e. a thief with monster strength, or a mage with high wisdom, or a warrior specialized in bows. Moreover, you can dual-class or multi-class, effectively changing the way your character plays - a mage/thief? Go for it. Warrior/druid? No problem. The flexibility offered was sufficient to generate unique builds.
Fallout had SPECIAL - limited amount of points to distribute between 7 attributes. From the get-go you can change the amount of points or attributes themselves with traits (gifted, bruiser, small frame). Then, as you mentioned, there are perks every 3 levels, and among these are stat increasing ones. Furthermore, the game itself has many places in which you can increase your stats (surgeries, modules, game story elements).
I would not call BG1 a semi-open world. You have a map of the Sword Coast, and this map is completely filled with locations - it's a 1998 open world. Smaller zones of more or less the same size that are connected to each other. The connectivity is crucial here, as the zone to the south is a direct extension of the north zone. This way, the entire Sword Coast is recreated. DA:I has multiple huge zones that are not connected, the world present in the game encompasses Ferelden and Orlais, yet we only get to visit a few small chunks (small in regards to the scale of gameworld) of the world. It's not like BG1. If anything, it more closely resembles BG2, which is set in Amn mostly, but you only get to visit a few locations - Athkatla obviously, de'Arnise stronghold, Trademeet and so forth. Upon release, BG2 received some flak for this approach, as gamers were not happy with the departure from BG1 map system. Even though BG2 has a few locations, they are all tightly connected to the story, unlike certain zones in DA:I.
The limited healing of BG1 results from the fact that yo cleric/druid can only reach level 7, which gives him access to level 3 spells at best. In BG2, pretty much without the level cap, you cleric/druid can be a healing machine. Potions are scarce, especially in the early game.
In BG1 the rest mechanic is based on entirely different concept. You rest when your characters are tired (which lowers their die rolls), to replenish your spells/abilities, as they are cast-and-gone kind of thing (there is no cooldown), and to heal your party. You rest because your mages/clerics are useless once they cast all their spells. You rest because your group is one hit from dying.
BG1 was about damage mitigation? With what? Protection from evil? Armor spells are useless for high AC characters, making them viable only for mages really, Blur is a solid spell, but requires sacrificing precious 2nd level spells slots (I'd go with Web and Stinking Cloud, for starters). Proper protection spells can only be cast from scrolls (few and far between), unless you have a cleric who memorized them.
Cleric/druid spells have a few more protection options with Barksin, Sancturay for a caster only, Resist Fire and Cold, and Armor of Faith which gets better as you level up. However, these are NOT viable damage mitigation options. They can help you avoid a hit or two, but won't dramatically alter the battle. Keep in mind that if decide to have them memorized, you leave yourself without healing spells, AoE spells, control spells and summons, which usually help tremendously during any battle.
BG2 is more about spells-induced resistances and damage mitigation, but again, it means abandoning the plethora of other, IMO more useful spells.
So ultimately, no. Your fancy comparison to BG1 does not hold its ground at all and is far-fetched. There are similarities, sure (you can always find some), but the formula is not even close.
Peace.