"Its the same mentality as Trump, "lugenpresse". A conspiracy theory that all the press are against them because they are so awesome. Why no one buys papers supporting them tends to desolves into basically everyone is idiots and accepts the press lies rather than they are a relatively fringe group in the larger society. "
Buying papers is irrelevant now. The purpose of the smears in the Telegraph, Mail, Times isn't to influence the people who read those papers but to dominate the wider narrative. So for example people are talking about Corbyn at a graveside rather than shite wage growth and productivity.
The idea that billionaire owned press being biased against socialist policies is a crank conspiracy theory is brilliant.
http://www.dailymail.co.uk/news/article-5401097/Jeremy-Corbyn-paid-Czech-secret-police-spy-claims.html
https://www.telegraph.co.uk/politics/2018/05/09/could-army-coup-remove-jeremy-corbyn-just-almost-toppled-harold/