Of course you're not arguing that arranged marriages are better. That's because they are worse, as is hunting and gathering as an economy and a lifestyle. Anthony Giddens argues that there's a worldwide trend toward increasing democratization of family life, and that this is a good thing. There's also a worldwide backlash against the trend. The point? When they get the chance to choose between collectivism and individualism, people know which is preferable. And please don't try to tell me the whole trend is just a product of capitalism. On the contrary, much of the trend is an unwitting (so far) slap in the face to all the repressive "family values" bullshit peddled by leaders of the status quo.
Sure, people have been happy in traditional societies, and we can learn some very important lessons from those societies. Yes, most traditional societies never had a great choice, due to the murderous nature of the early ambassadors of modernity. Nonetheless, what do people prefer when there's an open alternative to the traditional way of life? The answer's pretty clear, if you ask me.