This is just being obtuse for the sake of it. Yes, technically nothing in the notion of a container necessitates that; containers are just a form of namespacing. Have a gold star for understanding that. But the fact is: the vast majority of containers in use are going to be based on some minimal OS image, which is what the commenter was referring to.
People use minimal OS images when they absolutely have to, but the ideal case is just your binary sitting there all alone. (Sometimes you need the tzdata files, SSL certificates, and other support files. But rarely a shell.)
I agree that the ideal case is just a single binary with minimal supporting data, but people using OS images is certainly the norm not the exception. To suggest otherwise is ludicrous.
