why do some girls extensions look so unnatural?

I thought the point was to look natural. Have your hair look like real human hair. There is this girl that wears a different wig each day. one day her hair is ear length, the next day it's down her waist. I am just thinking this looks like a hat not hair. I don't get it. why not keep the same length and at least look natural instead of looking like you stole Barbie hair from a life size Barbie doll??? if you are going to wear extensions shouldn't it at least look blend in with your hair and look like it could have grown from your scalp??? it looks really bad and I am just trying to understand the mentality behind it.