Efficient market hypothesis under attack

Note how this article confuses two "definitions" of the efficient market hypothesis:

• You can't beat the market.
• The market is "rational".

I don't even know what the second definition really means, so it's not surprise that I subscribe to the former definition. So does the author of the article:

Unless you’re Warren Buffett, an index fund is where you should put your money. Even people who don’t follow that advice know they should.