They asked if I wanted my dissertation to be available, free of charge, to anyone interested in reading it.
Clicking on "yes, I want to make it available for free" would cost me something like $800.
Clicking on "no, I'll let you charge people to see it" would cost me nothing.
Having just finished, and being in debt to do so, it shouldn't come as a surprise that I wasn't rushing to pay even more. So now, if people want to see my dissertation, they have to pay -- or be part of an institution that pays an annual fee to ProQuest. (BTW, e-mail me if you want a copy.)
My guess is that it's similar with other journals. And while professors have more than PhD students, they have limited enough research funds that they'll hold their nose, save the money, and keep things behind a paywall.
Which is totally outrageous. It's about time that this change, and I'm happy to see what looks like the beginning of the end on this front.