I did mostly linux kernel stuff for over a decade. The vast majority of developers are quite helpful to people with little history in the community. As others have pointed out, generally this sort of stuff is aimed at people/projects that have a history of good work and then fall short of expectations.
If you submit a patch (formatted as per instructions) to the list, generally it will either get ignored (in which case you might want to contact the maintainer for that area) or else you will get some comments. Note that not eveyone's comments count equally--ultimately the subsystem maintainer is the one that will apply the change.