I like the origin system, for what it's worth (not much, I know...). I'll definitely be doing custom character playthroughs (probably multiple) but I also intend to play every origin character at some point. I think our custom characters will shape up to have more identity and impact on the story in time. It's already hinted at in the dream sequences and with the choices you make in regards to Dream Daisy. The first part of the game is really just setting the tone and introducing the various characters. The story is just picking up. It's difficult to see because we have barely 1/3 of the story so far, but I do have faith that Larian is working to provide the best experience that they can. The custom characters haven't had much story time for players to flesh them out, and I doubt people want for the custom characters to be handed a fleshed out story right away? The origin characters are able to have complex stories at this point because they don't require the players to design them through gameplay interaction. Basically, we don't have the full story yet.
I agree with Alexandrite, Blackheifer, and Evilvik on this. I'm looking forward to playing the origin characters. Is it really a waste of resources for the game if there are people that want to and will engage with and enjoy the content? Players who don't want to play that way aren't required to engage with them at all. Time will tell if they end up missing out on a majority of the story. I'm hopeful that Larian has thought about and will address this, as they intend for multiplayer (and thus parties without origin characters) to be a big part of the experience. I disagree that the world and characters are bland and flat. I don't have as many hours in the game as some people here, but I've had a great time! I also like a good story, and have really enjoyed what I've seen of the companions' stories so far. I understand that not everything is perfect, but it's also a work in progress. And it is getting better. I've seen that from videos on Youtube of early gameplay and my own playthroughs this latest patch.
Edit: Before people come for me! I do want to say that I recognize the issue people are raising about this being a DnD game, where character customization is one of the foundational aspects of the game. Sometimes I do wonder if having so many origin characters is too ambitious. I'm just personally enjoying these aspects and generally have a positive outlook on it. I'm not trying to dismiss anyone's criticisms (I think many of the concerns have validity even if I disagree with some of them) but I've been following this thread for a while and want to provide a different perspective.