I think it is your right that you promote the digital editions software to apply DRM to most of the books in the industry. Which means that almost every customer has to deal with your software. And that would be fine for me. The only thing that i think is wrong that you make use of the older generation by adding a option to install Norton software for 30 days. That is just making use of your position.
The millenial generation knows better that to install that unwanted pieces of software! so for me it is not that much of a problem. If you want to do DRM make it in a way that is not so annoying to people actually paying for the content.