With two Onion articles ridiculing South by Southwest Interactive this year, I've heard a few folks wonder aloud if SxSW has gone too mainstream. And indeed, SxSW is larger than ever. The Austin American-Statesman writes: This year’s SXSW Interactive proved the biggest yet with 30,621 paying attendees. That was 24.6 percent larger than 2012. The festival had predicted only 5 percent to 8 percen…