i guess its because of the microsd.. since the phone able to store 32gb of microsd..

for me i take 16gb+32gb card will be enough though..

32gb is more than enough for normal users
those who need more storage are going to fully utilize the phone multimedia capability. like putting in tons of movies, tv shows etc

ya zzz
it just like computer, store in hard disk vs pendrive
just act as phone storage = hard disk while microsd = pendrive