They add up in a data warehouse that IS mined with “data-mining” software.
The error report for software undoubtedly includes some kind of indication of what the error actually is (irrespective of whatever text you may add to say “it’s this, that and the other thing”), and the accumulation of reports indicate where users have problems.
As a human example, I didn’t really start to “learn” Excel until I started trying to help other people with it. They had ideas of things that they wanted to do, and which I hadn’t ever considered before. Combining their “how do I do this?” with my own nascent talents has enabled me to do things that neither of us had considered, and so that goes.
For another example, when I worked for an RTA (ready-to-assemble) furniture company in the early 90s (think Sauder and IKEA, in fact, we made some IKEA furniture for them under contract), I often took service calls from frustrated customers and made my own database of what they had trouble with, what was short-shipped or damaged in the box, and what instructions were not clear. I guarantee that we made changes to the product, to the packaging, to the production and to the instructions, just based on my own home-made database.
The VP of Production didn’t like the mistakes we found and pointed out to him, so during an intramural power play after his promotion he fired my boss, the Director of Quality, and the next day he had me fired. And the company was out of business a year or two later. I’m not saying they went under because they decided they didn’t need to listen to me any more; I’m just sayin’ ...