Wow.

Why do people pierce babies ears so young?
I haven't read all the responses yet so someone may have already answered this, but it's quite common for Drs and piercers who are asked about the procedure, to recommend that it be done either BEFORE 8 months of age, or then left until after the child's 3rd birthday, because that window in between is when littlies discover body parts and start to pull and tug at their bits and pieces, especially their ears etc, increasing the risk of infection. It's thought that piercing a baby's ears before they hit that curious and capable 8-month mark will decrease the risk of infection or damage to the lobes because they haven't yet worked out how to pull or touch their ears, and they can heal without interference, and it's easier for Mum to clean them as they are more likely to be able to sit still/be held still while it's being done twice daily.
I didn't want to get the DDs' ears pierced that early because I figured it was unnecessary, and FWIW when I took DD1 to get her ears pierced at 17 months (ish, I can't remember the exact age but it was when she started daycare so that's how I remember), she had been asking about 'getting pretties' for a while (DH and I are both tattooed and pierced and she is fascinated by them). I fully acknowledge that she was far too young to understand me when I explained that it would hurt and that she would have to let Mummy help clean them while they healed, but that explanation didn't put her off and she was really excited about getting her ears pierced. I would not have put her through it if I didn't think she could handle it, but this is the kid who never sheds a tear at vaccinations and jumps right back up and keeps going even with a skinned knee. Pain doesn't bother her much, and she was fine as soon as she saw in the mirror that she had the earrings she wanted.
Sure, I could have waited, and yes, I do sound like a hypocrite when I speak so adamantly against infant circumcision, but for me, the two procedures are very different things.

As for wanting to 'feminise' a little girl by getting her ears pierced, YES. I have often considered it for DD2 purely for that reason - I dress that poor kid in head-to-toe pink, frills and all the rest, and people STILL say, 'What a cute little boy, look at those curls!' Right now, that's not reason enough for me to get her ears pierced, she's not quite as advanced as DD1 was at that age and therefore wouldn't understand, so I won't force it upon her, but yeah, I can see why parents choose to do it if they're constantly trying to find ways around the awkward, '...but she's... a she?' thing.