Somebody who is not a software developer or is a junior one who only ever worked in one or two major projects and got lucky (really depends on the country and the industry) might believe it.

It's hardly unusual for people who only ever worked in one place to think everything is like that, and some of those do get lucky (not all software development environments out there are like the US Tech Industry) and end up right after Uni in a place with some good senior techies that make sure environments are properly set up.

Also in-house development in industries were software is mission critical and new versions breaking Production might result in massive losses or death (for example, Finance) always have proper Testing and Staging environments - you don't really want to lose millions of dollars (possibly hundreds of millions if unlucky) by having all the traders in a Trading Floor twidling their thumbs because somebody didn't do, before pushing to Production, proper integration testing in Staging of some comms protocol changes done for two different systems.