It's very concerning that there is so much influence concentrated within such few hands. However I have to ask - would the WSJ would be so concerned if Google or Facebook were conservative leaning outlets? Normally the WSJ defends this kind of duopoly kind of thing - if either Google or Facebook had some sort of right side leaning the WSJ would be preaching to us about the genius of capitalism and the wisdom of the m…
So I think it's totally fair to call out perceived inconsistency in the WSJ position. Maybe the WSJ has a blind spot where they are more willing to accept consolidated power when it favors them. But I think that illustrates exactly why viewpoint diversity is important. WSJ will have blind spots sometimes, but other times they may be able to call other media on their blind spots.
Put another way, you can think of society as a whole as a mind. Just like our individual minds, the societal "mind" can have conflicting or competing ideas. The mind functions best when these different thoughts can "have it out" and try to convince each other that they are correct.