Survivorship bias is real, but is missing the important piece of the story when it comes to software, which doesn't just survive but is also maintained. Sure you may choose to discard/replace low quality software and keep high quality software in operation, which leads to survivorship bias, but the point here is that you also have a chance to find and fix issues in the one that survived, even if those issues weren't yet apparent in version 0.1. Author is not trying to say that version 0.1 of 30 year old software was of higher quality than version 0.1 of modern software -- they're saying that version 9 of 30 year old software is better than version 0.1 of modern software.