Not for attention per-se, but to be able to sell their bodies for higher price.
I would like to get mine done someday, not for attention, but because I am very small chested and would like them to be a little more proportional to my body. I think a c cup would be fine. and yes clothing would be more flattering
For their self-esteem.
I don't see how reasons matter as long as THE WOMEN in question are happy :)
I think they get it to feel more secure about their boobs.