To echo what others have contributed, I see this as well in the aerospace industry. Project managers are often willing to accept software as a black box component but wouldn’t dare accept hardware without a high level of quality pedigree. I think some of it is the tangible nature of hardware but also because systems engineers on these large projects almost never come from a software background.

I often wonder if the cavalier attitude towards treating software as an engineered product is because the software industry is relatively young. I imagine a lot of the cowboy attitudes we see in software were also prevalent in, say, pressure vessel design 130 years ago before adoption of strict design standards became common practice. I’ve heard it said that software is very much in the cave drawing days by comparison.