This is very often misinterpreted to mean that you should use exiting stuff even if it doesn't fit your purpose. Obviously there need to be products that fit your purpose BUILT by someone for you to buy one. Several times I've been in a position where people around me pushed me into using something that remotely looked like it solves my problem. Since I was the one doing actual analysis and work, I knew I'd spend a lot of time digging through internals of said product to bend it for the use case. They also claim that they don't believe that there's not some existing software that exactly solves my problem and I'm creating something just for the sake of it. Let's be honest, these people are full of crap thinking about software engineering only superfluously. There's no silver bullet.