In some cultures, it is what is done. Much like 'circs' for little boys, in some cultures little girls are to have their ears pierced young. Not saying I agree with it, but it is a cultural thing that I don't have the right to question as I do not know enough about the culture.
I had mine done at 3-4yrs because I wanted them done. Cried like a baby, then showed them off to whom ever would look. I have had up to 5 in one ear, and 3 in the other - before I had an industrial (long bar across the top - 2 holes) and another odd one done, and have had various body piercings. And have 12 tattoos = so pain's never been a problem for me. Thought, may have started a 'bad' habit getting them done in the first place!
I do think I will wait until my daughter (or son) ASKS for them, but I am not going to judge someone who does it because they are required to by culture - just like I do not judge if one must circ their son.