I'm concerned that many programmers who use mostly OSS (e.g. web developers) never submit a single patch to any of the multitude of projects they benefit from.

I'm concerned that many programmers who use mostly OSS (e.g. web developers) never submit a single patch to any of the multitude of projects they benefit from. Clients save millions of dollars because dev agencies leverage tons of free/open-source software. If programmers do a proper job they should routinely come across bugs or incompatibilities in at least a few of the myriad gems, node modules, etc. What could be more natural than for the developer to fix the bug and send a pull request back to the maintainer? When looking at candidates I almost always find some correlation between a meaningful public commit history and quality.