Indeed, that was an earlier iteration of the internal argument (the appeal to authority of Facebook and LinkedIn and their well known embracing of HTML). What you say is absolutely true, and the truth is that these shops are staffed with often pretty standard technology guys, but because they're big everything they say and do gets more technically credibility than it perhaps should. Recall when the startup world was rushing to listen to Digg's profound statements on databases (most of which we quickly debunked)