Presumably because Elon himself will be involved in the design, and Elon, as we all know, is one of the world's great thinkers. ;)
I recently spoke with someone who quit SpaceX because (among other reasons) they felt Elon was a meddling micro-manager. That's just one anecdote, of course, but the Internet is full of them, replete with summary firings (https://www.businessinsider.com/tesla-elon-musk-ruthlessly-f...), worker safety issues (https://www.washingtonpost.com/technology/2021/03/12/hundred...), and just general bullshit (https://www.reddit.com/r/EnoughMuskSpam/comments/9e360m/elon...).
I don't deny that his public image, for years, was an overall positive one. I really enjoyed Jill Lepore's digging into it here: https://www.pushkin.fm/podcasts/elon-musk-the-evening-rocket.
But it seems like people who worked with him knew, for a long time, that he was full of shit. And increasingly, the public seems to as well.
From what I heard about SpaceX it seems to be a place grads go to burn out while being paid below market rate simply because they're excited about the idea. Maybe that impression is wrong, so I'd like to hear other perspectives.