Not true. Think.
A render is alot harder to make then any brush. Any brush made on any site can be made by anyone. However i did realize there was an error in my statement, it is art. Its just not the same as making it yourself though.
EDIT: I actually dont use other peoples brushes, unless the they ask for me to test them for them. I would suggest that anybody who wants to be a true artist do the same thing. You cant use some one elses art to make your own. Its not truley yours then. Its illegal to use somone elses brushes for profit too, so think about that.