Hand-written code never implied much about quality no matter the author, especially as we all use libraries of reusable code of varying quality

Not much, but infinitely more than now.

If someone puts weeks and months of their time into building something, then I'm willing to take that as proof of their motivation to create something good.

I'm also willing to take the existence of non-trivial code that someone wrote manually as proof of some level of competence.

The presence of motivation + competence makes it more likely that the result could be something good.

Agree that just being hand-written doesn’t imply quality, but based on my priors, if something obviously looks like vibe-code it’s probably low quality.

Most of the vibe-code I’ve seen so far appears functional to the point that people will defend it, but if you take a closer look it’s a massively over complicated rat’s nest that would be difficult for a human to extend or maintain. Of course you could just use more AI, but that would only further amplify these problems.