And what's the problem with that? People are entitled to their opinions, including journalists writing editorials.
Besides, the whole EU critique is such an old hat. In the 80s and 90s there was overwhelming critique on the EU from the fringe left in many countries. Now it's also coming more from fringe right-wing parties. Apart from that, not much has changed. The same old story, using the EU as a scapegoat to get voters, while the majority does the right thing. Then, when those parties get to power, they usually change their mind in light of the facts. (Typical example: The Green party in Germany, which was, of course, very anti-EU in the 80s. Now it's the AfD from the right-wing with the same silly arguments.)
Anyway, stop blaming journalists for not sharing your opinion. It's not their role to please you, and if you want to hear what you already believe, there are plenty of 'non-mainstream' media, i.e., personal blogs and politically coloured news aggregation sites, to confirm your opinions.
The idea is patently absurd that people don't get enough choices in the media nowadays and therefore could be mislead.