[pseudostem]

Exactly, even large textfile based DNS servers have capability to "compile" the textfile to a db file for faster access.

[crabbone]

So what if they do?

This file is a public interface exposed by Linux to other programs. So what if Linux caches its contents when eg. Python interpreter on launch will read this file. And it's not coming from some "fake" filesystem like procfs or sysfs. It's an actual physical file most of the time.

[fsckboy]

the python interpreter reads /etc/passwd on launch? i guess it's looking for home directory