Yup. They're called, "people who believe that some sites should be supported by their primary revenue model."
I leave advertisements on when visiting
Seems a fair thing to do in exchange for their services.
Sorry, but if the only way you can monetize whatever you are doing is by placing ads for other people / organizations on your page, then maybe what you're doing isn't worth much. Everyone wants to think that whatever they have is worth something, and unfortunately for them that's usually not the case. That aside, I appreciate Slashdot's optional ads and I don't use Adblock on their site, but I leave it on for basically everyone else.