For what it's worth -- I agree with you and is why folks are flocking to docker/kubernetes and devops tooling like Terraform. I just think you're missing the scope of it. Say for example, a big box store, they might have 500 locations, and all the sudden they buy a few more companies, and merge all this stuff under a single brand. All the sudden they have tons of systems all over the place, lots of existing platforms that need to talk to each other, and staff that are resistant to change. This isn't "newly designed stuff" it's systems that sort of organically grew over a long time. You're talking lots of different operating systems, networks, front-end/back-end systems, www corperate site, mobile site, rewards sites, all sorts of internal support applications, pos system backends, etc. They probably have 20+ different large database systems and they might not even know all the apps connecting to them. I actually worked with a company like this on a few cloud projects. It was amazing to see the complexity. This is the type of stuff that's running large parts of companies that you interact with on a daily basis.

I guess what I'm getting at, is that sure if they design new things they will follow modern patterns but there is so many things that are not modern. They don't have the time or incentive to just go and rebuild all this stuff. There is zero benefit to them on a bottom line, unless there is some burning fire, a way they can extract more money, or save tons of money. So, they just keep them on life support and run in a keep the lights on mode until something happens. These are the systems all sysadmin's just wish went away and there's many of these types of things all over the place.