The thing I really like about libraries is that they exist to serve their communities. That means the public library in one city could potentially be completely different from the public library in another city, provided that the first city required something completely different than the second. And sure, some people think that libraries are a place where you go as a kid and then never go again, but for a huge portion of the population, libraries serve a critical function as an information hub and community center.
So, you'd think that people would leave libraries alone and just let them serve the public. Unfortunately, that's not the case. A lot of people (who neither represent the will of the entire community nor possess a degree in Library and Information Studies) feel obligated to tell libraries what to do.