You know what else these websites could do to stop people from using ad blockers? They could try to pressure advertisers into behaving responsibly, for once. Here's a brief explanation of how to advertise in the web responsibly:
1.) Limit the size of each ad, so as to ensure the users' bandwidth isn't completely saturated with ads.
2.) Stop the drive-by downloads.
3.) Stop the Flash Player-based advertisements. Flash has only continued to suck for the last several years.
4.) End the "click here to download" advertisements.
5.) Stop spying on users. At the very least, honor DoNotTrack headers. Of course, considering DoNotTrack has been around for at least 6 years, I don't think this will happen anytime soon. Of course, a better solution would be to stop tracking all users.
6.) Web designers: keep the quantity of advertisements to a reasonable level. Too many ads make websites slow and borderline-unusable, while saturating the users' RAM, CPU, and network bandwidth.
7.) Web designers: stop with the pop-ups and pop-unders. People have been complaining about these annoyances for 2 decades, now. This unwillingness to listen can't possibly lead to anything other than a raise of content blockers.
There are all known reasons why people use ad blockers. Until these issues are dealt with, ad blockers will only continue to grow in popularity. Of course, considering the industry's refusal to change, I doubt ad blockers will go away anytime soon.