Really, all it is is a convenient catch-all term for people who build their own stuff. There are lots and lots of people, indeed I would say most of the people of the western world, who never make things for their own use. They buy stuff from manufacturers all ready to go. To take this even further, there are people who have the technical and design skill and work for these manufacturers who believe this is the only way things should be. I disagree, but that's just my opinion.
Referring to "makers" within our circle is more than a little redundant and confusing, because we're all used to designing and building things to solve problems, whether for work or around the house. The term is designed for use with people who don't.