Yea the guy who wrote that article is an idiot. But you drop some names and you get you idiot piece picked up by the likes of Marketwatch and drive traffic.
Some members made some very good points here that competitive advantages are not the same as monopoly power, etc, so I won't delve into those things. The truth is that if there's one thing that Buffett understands is competitive dynamics and he probably understands that better than anyone else. Berkshire invested in companies with monopolistic, near monopolistic, or oligopolistic attributes (I'll call them monopolistic here for short).
But what the idiot writer misses is that Berkshire didn't make money because of these monopolistic dynamics of these companies. Berkshire made money because they've bought them at a discount to intrinsic value. Furthermore they made money because some other idiot agreed to sell it to Berkshire below IV. I don't really understand what the author expected Buffett to do. Some guy comes to him and says I want to sell you this very profitable company with a great competitive position for half of what it's worth. Then Buffett should say no, I don't want that, I want to go out there and buy some piece of shit for a lot of money? That has nothing to do with capitalism, or any other economic system for that matter, it has to do with whether you're smart or stupid.