Some of the members who fill requests have been burnt in the past by people who do not pay the points they promised or who take the shared by request item and upload it onto paysites after being asked not to do so, therefore it's understandable why they would be reluctant to share with a newbie who hasn't shared any items of their own on the blog or interacted with the community other than to request items and download from the blog using the accumulated daily points.
The quickest way to build a good reputation is by sharing your own assets,(check first to make sure they haven't already been posted)take part in art competitions and chat to other members here in general chat.