That's not to say that that's a good thing, mind, it's neither good nor bad, but it's a fact that maybe 1 in 10 people employed in the software industry will ne

That's not to say that that's a good thing, mind, it's neither good nor bad, but it's a fact that maybe 1 in 10 people employed in the software industry will need to know big-O, perhaps even less than that. I don't think the ratio is that high, simply because most people who do software development aren't in the software development industry. They are members of an IT team in an organization who profits come from the sales of things other than software. Although the organization they are at might benefit from software that solves real technical problems relating to their product line, most of the time, they are just writing ETL programs that require little more than getting table names right. Of the people who work at companies that see software development as one of their core disciplines, I imagine the problems are sufficiently hard to make some knowledge of theory useful.