This "15 posts" thing isn't a good idea

I can offer my thoughts as a new member

I do think that 15 posts requirement is good. By the time you get 15 posts, you will have some idea of the community, you can also make a decision based on time you spend here. If a user likes the comminity he will stay and vice versa.

On the other hand if there was no requirements, people will simply download the file the leave. The community suffers in this way.