Intelligence only affects your languages known at character generation, though. In D&D-world, people just spontaneously pop out of nowhere knowing Int+1 languages, and can learn as many as they want with skill ranks, sometimes becoming fluent in foreign tongues overnight. In the real world, you're born, and develop languages through exposure and/or study - i.e., the Speak Language skill. The number of people with more than one 'native' language are vanishingly few, so by this logic, no human being in the world has more than 11 Int.