Why do people ask that as if it's unexpected? Why would you expect the default libraries to contain EVERY SINGLE COMPONENT EVER MADE? Have you any idea how vast a pool of parts that would be?
No, the short answer is that you should only expect the installed libraries to contain a selection of common components. Anything else, you should expect to have to make your own library part. There are plenty of tutorials out there on this essential part of the eCAD user's skill set. It's not optional. It's fundamental.
