As with most things, people's experience is colored by their previous experience. There are people who work on 10MM LOC codebases that say "oh well you don't even have one of those", or for example, take Google's C++ codebase, which last I saw is estimated at something like 2 billion lines? Yes, that's a bunch of small projects, but since it's in a monorepo and uses one big build system, to people thinking about scale, they consider it one, or so I've heard.

Add in a general sense of bragging rights, and well, I've heard people say "call me when you have a real project" about more absurd (to me) things than just this in the past...