Nope, not a straw man at all. In fact, it's common enough that the "library lady" is a stereotype.
Libraries may have changed a lot in the last few years, but the staff of most libraries are generally still civil service hires, and it usually shows. I'm telling you that most librarians have jobs to do and job priority generally doesn't include customer service. And pointing to signs or computers isn't customer service.
I don't dispute that your library is different, or that your staff is different. But my experience at every library I've visited has been that there are some helpful workers who don't know where stuff is, and older workers who do know where stuff is, and don't want to deal with patrons. If I had a nickel for every annoyed sigh I'd heard when asking where collection X was...and even though the collections had moved from where the signs were indicating.
Your library must not be part of the Metropolitan Cooperative Library System of Southern California, because we give custormer service a high priority. I have served on the reference desk at six libraries, and at each one, the staff has always done its utmost to satisfy each patron's information need.