Quite possibly because:
a) You have no concept of how long it takes to make quality content
b) Some people actually have lives besides creating free content for people. Important things like working a job to put food on the table or a roof over your head. Spending time with strange people that live in the house that some people call a family perhaps?
You've got to understand that you get your choice of service: good, fast, and cheap. Pick any two you'd like:
1) Fast and cheap isn't going to be good.
2) Good and cheap isn't going to be fast.
3) Good and fast isn't going to be cheap (or free).