Why do people think libraries are expendable?

I'm a fan of "I Love Libraries.org" on Facebook. The administrator asked the question, "Why do some people think libraries are expendable?"

Here is my (long, especially for a mere FB comment) response:

Mayor Menino of Boston is planning to close down some neighborhood branches of the BPL. His justification is that we do not need so many sites for accessing resources now that we have resources available on the internet. He says we have to move into a 21st century model. What that statement makes clear is that libraries have not done a good enough job selling their relevancy for the 21st century. People, especially people with lower incomes, use libraries to access said internet resoucres, since they have don't have access at home. Libraries are social centers as well as "scholarly" centers (for lack of a better term). If a politician can get away with such statements with minimal protest, then the instution needs to focus on adequately promote their relevancy and vital role in ongoing changes in information literacy and how they help the community with those rapidly growing innovations...my, my, that was long! I didn't realize I had so much to say about it until now!

What do you think?