Useless article. This has nothing to do with "openness", just marketing: what is Google's incentive to building the site in the first place if they can't make people download Chrome to view it? That said, they could at least add a "Try it anyway" button for other browsers.
The reality is that Google is not some benevolent open source company as they're often portrayed but are a gigantic advertising company with a financial incentive in getting you onto their products, which gives them data to index for advertisers. Chrome, for example, automatically interfaces with the Google search engine by default. They don't care about openness--that's a feel-good buzzword they use to make techies like them.
Google defenders have gotten worse than Apple defenders when it comes to justifying absolutely every shitty move Google makes.