Oh yeah, just like leftpad was not a technical issue. But it's still a good analogy of a big problem the JS community has.
I think leftpad was a bit different. Programming in JS you often need some dependencies. You could start from scratch and do everything in your own, but that's a huge time / resources sink. Using docker you can always start from scratch and it's barely any harder than using some huge starting image.
- No packaging, little doc, etc. "Just use the docker image".
I'll take a project with a dockerfile used for CI over a project with short setup instructions. The first one is less likely to go out of date, or be incorrect. (Ideally it would have both, and a good operations manual. But given only those two, very common choices)
- Docker images are big huge binary you download from internet and run on your server.
I agree this is how most people use it, but you're not forced to use it that way. You can deploy memcached based on 200MB Ubuntu base, or a custom images containing the lsb layout + libc + few devices, totalling ~8MB. The huge images are a documentation/community issue, not a technical one.