Newspapers and magazines were profitable for centuries. Like many other industries, they've struggled to adapt to the new norms the Internet brought about.
Many newspapers, but by no means all. British national newspapers have, as a class, lost money for decades - plenty of people have been willing to subsidise the losses in return for the influence of owning one - so the economics were bad (and now getting worse).
Owning a monopoly city newspaper in the US, with a captive advertising market, was a lovely business until recently though.
Many of their competitors have been profitable for a while now. There's no incompatibility between capitalism and "real journalism", the problem with the guardian is in fact their complete disinterest in capitalism - hence being a literal trust fund baby.
Maybe real journalism just isn't profitable in a capitalist economy. This model works for organisations like NPR and Propublica.