Perhaps. There are many people, even in the IT industry, that don't deal with containers at all; think about the Windows apps, games, embedded stuff, etc. Containers are a niche in the grand scheme of things, not the vast majority like some people assume.
Really? I'm a biologist, just do some self hosting as a hobby, and need a lot of FOSS software for work. I have experienced containers as nothing other than pervasive. I guess my surprise is just stemming from the fact that I, a non CS person even knows containers and see them as almost unavoidable. But what you say sounds logical.
Self-hosting and bioinformatics are both great use cases for containers, because you want "just let me run this software somebody else wrote," without caring what language it's in, or looking for rpms, etc etc.
If you're e.g: a Java shop, your company already has a deployment strategy for everything you write, so there's not as much pressure to deploy arbitrary things into production.
You build new image with updated/patched versions of packages and then replace your vulnerable container with a new one, created from new image