AOL and similar services, like CompuServe, were founded while the Internet was still restricted to "non-commercial entities". They were giant, nation-wide bulletin board systems. They worked and were profitable. At the time they connected to the Internet, it was seen as a way to increase profit. But then came "big content". The major ISPs now perceive that forcing the major content providers to directly pay for access will increase their profits even more.
Will this really work? I don't know. But it will have the side effect of squeezing out the little content providers. The little ones will be dependent on the tolerance of the big ones to get their content seen.