Marriage of attraction is a gamble anyway so you might as well marry into a family that is similar to your own and make that much less of an adjustment. But the 'love marriage' as it is called is equally common in India now. But it would be interesting to do a comparison of what would work better. Marriage is hard work and it is a gamble.
I guess the real reason that my wife and I had children is the same reason that Napoleon had for invading Russia: it seemed like a good idea at the time.