[fao_]

How many times have you altered Firefox, though? Or Chromium? Or GIMP? Or any other large software project?

Free as in freedom doesn't mean shit when codebases are so large as to be inscrutable and induplicable.

[blooalien]

While I myself have only modified smaller codebases, modified forks of Firefox, Chromium, and GIMP (among many others) do in fact exist. Some of those forks have even gone on to become quite popular (although none yet as popular as their parent codebases).

[userbinator]

Meanwhile, people have been patching and modding Windows despite the lack of source code.