Some are (at least partly) accepted. Others are not but lead to intense discussions, which is kinda flattering... Reinventing your own wheel is, most of the times, much easier than spending time on mailing lists, adapting your implementation, testing and documenting everything. On the other hand, hard-coding your own stuff for any need is far less rewarding than contributing. Open source communities are, most of the times, much more organized then many companies.