Genuinely curious since I see a lot of people complain about it. I don't hate the concept but I never see myself playing the origins and I kind of wish they would redirect resources to making the PC more interesting.
On the one hand, I feel that all I have heard so far is only some general gist. Basically, you will have special scenes giving you a bit more insight into the character's backstory and personal quest. Though you should learn most of what there is to know about a character if you travel with them as a companion in your party, I would hope. On the other hand, I'm in the camp of people who have custom characters in mind already, each with their backstory, personality, etc. I have played the old Infinity Engine games, and even some TT RPG back in the days. So whenever I can create my own characters, I do. I doubt I'll ever play as an Origin character.
But many video game RPGs, from Final Fantasy to Zelda to The Witcher, have you play as pre-set character X or Y or Z. I can see many players going for that.
Larian seems to aim to cater to both audiences. In a sense, why not. So long as they don't overspend resources into a feature that half the players will use, when they could spend more time working on things all the players will use (the UI, the writing, etc).