Some reasons why BG1 was a lot better than BG2 (for the inclined monocle wearer):
- open world structure as opposed to the sequel's hub based linear structure
- down to earth world and atmosphere that actually felt like a real medieval fantasy region, as opposed to the sequel's "trying too hard" uber-epic world where you couldn't walk two steps without stubbing your toe on a dragon, demi-lich, or a spaceship from another astral plane
- more fun and faster resolving combat, with reasonable low-level abilities and spells, compared to BG2's endless and super slow mage duels
- far better story: the mystery of the iron shortage and Gorion's murder slowly coalescing into the political scheming of the Iron Throne and finally into your divine sibling's plots, against some whiny emo elf moaning for hours about his lost wife
- no romances
- significantly better loot tables due to scarcisty: finding a magic item in BG1 was a treat and an event, it took forever to save up for the non-magic suit of plate, meanwhile in BG2, with its annoying epicness, you were throwing away +3 items in the starting tutorial dungeon left and right
BG1 was a chance for Bioware to become a special studio, if they only followed what it started. Instead they went into a lot of different directions with BG2, almost all of them being harbingers of the studio's eventual decline: companion romances, hub based structure, and way too much epic bullshit.
Complete and utter horse shit:
1.)Open World vs Hub is a matter of preference and is in no way an objective way to measure of the quality of the game. In BG 1s case, the open world ness means very little considering that a large chunk of those "open world" maps are mostly empty with 2-3 boring trash encounter and little to no loot. The main quest is also unabashadly linear and has to be solved in exactly the same steps even if you might find something out by accident or own deductions.
2.) Completely subjective and again not an objective measure of the quality of the game. BG 1 is a very bog standard low level fantasy D&D adventure of which there are literally dozens around, more if you count in PnP. Low level vs high level is entirely up to taste. That does not make BG 1 a superior "monocled" game, far from it. As to stubbing your toe to encounter "uber epic" enounters, that is for the most part limited to ToB which most fans agree is the weaker part of SoA but it is also fairly short by comparison. Also what are you going to do to challenge a high level party at that point? Most normal enemies are trivial at that point.
3.) What are you talking about? Mages without SCS are mostly cake walk unless you are too stupid to either let your party arcane casters have 2-3 Breaches memorized, maybe a Secret Word to take down Spell Trap or fail to use AoE which is basically not blocked by anything outside of Spell Immunity which is rare without SCS. The only mages that give serious trouble are super high level mages like Lavok, Liches and Kangaxx as it should be for such legendary fiends.
4.) Nonsense. The story of BG 1 is a bog standard conspiracy with the only minor twist being that the end villian does that to ascend to godhood and that is not even that uncommon either that a villain wants to ascend to godhood. By comparison Irenicus is much more interesting. At least he gets fleshed out a little, what to you get to know about Sarevok in BG 1 apart him being the PC's half brother? Nothing of substance Sarevok is a very one dimenional primitive villain with the barest minimum of basic characterization behind him.
Also Irenicus is "emo for hours"? Have you actually played the game? For most of the game he outsmarts and outmuscles everyone including THE massive secretive mage society which controls everything magical in the kingdom of Amn and who no one can go against yet he not only destroys them but completely takes them over including turning the previous leader into a gibbering imbecile through experimentation. Hell who thought he was an elf upon first impression? He most certainly did not look the part. Sarevok is a joke compared to Irenicus, if not for story reasons, Irenicus might as well have caught Sarevok and submit him to the same experiments he did upon the PC and Imoen and there would have been nothing that insiginfiacnt speck of dust called Sarevok could have done to prevent Irenicus using him like a lab rat. Also yet again no actual objective argument was made, but who cares about facts when your feelings matter more.
5.) The romances are completely skippable and have little impact on the actual game. They are also tiny in term of content, probably not even 0.5% of all of SoA even less if you include ToB. Literally a non-argument.
6.) The loot is banal shit boring in BG 1. The best weapon you can find is a +2 Longsword which deals extra cold damage, wohoo! Staff of the Magi alone shits on every single piece of loot in BG 1.