If people are forking your project instead of giving you patches, it probably means 1 of 3 things:

1) You aren't going the direction they think you should go. If this is the case, you don't want the patch anyhow.

2) You have made it too hard to submit patches. They actually found it easier to manage the project themselves rather than go through your patch submission process. Ouch.

3) They think you're doing a bad job as project manager. They would never submit the patch to you anyhow, so nothing is lost by them forking.

And don't forget that if you want the patch, their fork is going to be under the same license, so you can just go grab it from their repo.