So rather than hand crafted quests where there are individual motivations for conflicting goals, the quests should be simplified to the point they are generically interchangeable between almost every character, with no differences at all based on the actual origin?
Doesn't that kind of defeat the purpose of having origins?
I am not making the game, I am only translating what the information is... and even I can get it wrong.
It is better to think of it that for SOME quests a character's personal ties to it become an entirely new dimension to it that they CAN explore or subvert (assuming it isn't a quest that must be unlocked through having a specific party member.)
So if the party is dealing with a bunch of thieves... That is a quest in it of itself (whether it be by destroying them, getting them arrested, or helping them)
HOWEVER! one of your party members is secretly a member. This means that they can work against you and help the thieves guild... It also means they can use their membership as an extra solution to defeat the thieves guild. If they are so inclined (and this information COULD be found out). All of these are perfectly viable solutions as is doing the quest typically in spite of this.
Larian doesn't put put motivations into your head. You do not have to work against your party and you are not punished for doing so, or if you are there are ways out of it.
The point of the competitive questing system is that unlike before where you had to sort of begrudgingly agree with one another all the time. Now? You have solutions to get your way and it is infused into the setting... AND quests can have quite a bit of depth to them to allow people to go after separate objectives that might not even be visible to another player.
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Not that there can't be multiple objectives brought on by multiple origins. Just that the system isn't set up so that every mission with one has all of them active at once.