What utter tripe from the Culture Secretary (who apparently believes that free is just another term for socialist).
Adblocking does threaten the business model of online newspapers and probably harms music and dvd sales. However, a large majority of the content available on the internet is provided by unpaid volunteers doing it for the fun of it or by organisations that have more sensible business models than simply beaming visuals at your unwilling eyeballs.
Many of the organisations that do make heavy use of advertising have slightly dubious claims to the propriety of their output anyway. Why should Youtube profit from copyrighted content that has been uploaded by a user? Similarly by what right (except for 'deal with the devil' terms and conditions) does Facebook harvest user details for personalised advertising hints?
More innovative internet entities go in one of two directions. The first is to keep it specialised, loyal and thus supported. Sites like Wikipedia and Board Game Geek sustain inherently useful communities that can be replied upon to put in a couple of quid whenever in a fundraiser comes round. Even freeloaders are likely to share the ethos and interests of the community and will help to create content that keeps the community vibrant and attractive. This approach is unlikely to be attractive to investors and shareholders.
Alternatively the more confident commercial operations can set up subscription models in the fashion of the Economist and Murdoch's evil (but savvy) empire. You don't have to sign up. The BBC will happily provide you with news for free. However, if you do you get access in a convenient way for an arranged fee.
John Whittingdale should read his job title and encourage such canny emergent strategies for internet management. Sticking his thumb in the dyke and griping about adblockers won't change things unless he is willing to back it up with tough legislation.