Except that I don't want to, nor do most other developers out there. Not because they necessarily lack interest but because there's a pretty good chance they're busy enough already.
You can say the same thing for any OSS project but then why is open source so damn popular? If you don't want to contribute then that's your own decision. No one is forcing you to do anything.
Because people contribute whenever they're interested in it, this is great in many different ways. However, using an open source project as an excuse to not do the work yourself (regardless of the reasons or the problems) is just silly.
Using open source as an excuse to do the part of the work that you are best qualified for, and opening up the rest to respective experts, is a pretty good idea.
