I don't think "差不多" means "Fail Fast, Fail Often".

差不多 literally means "not much difference". It's usually used by Chinese workers to dismiss shortfalls in quality/quantity that are, in their view, inconsequential. I'm also not sure it's prevalent enough to be a "culture", though I remember reading several-year-old blog posts about it.

I think of it as a guy building a shelf. He hangs the shelf, puts a level on it, and it's clearly not level, but only off by say, 2 degrees. Job done. Pay me. I won't mention to the person who hired me that it's off-spec.

To be fair, this happens all the time in the US, that's why we have building codes, building inspectors, etc.