Why by default Dropbox allows us to only have a free 10 GB of disk space?

I believe even this is a great freebee which we should be thankful for because remember the notion that nothing is for free wither we will give our time or money to buy things of convenience for us. Dropbox is a big convenience for professionals, students, and household people and certainly, those who are making it come to us need to make some bucks so give them some space and let them have some money out of this great app. Cheers