New warnings usually do not indicate real bugs. Sometimes they do, but usually they are false positives. -Werror causing a build to fail is strictly worse than

New warnings usually do not indicate real bugs. Sometimes they do, but usually they are false positives. -Werror causing a build to fail is strictly worse than the alternative (working roughly as well as before, sometimes slightly better or worse due to new optimizations). This is the direct cause of "software decay" here. The software would not "decay" nearly as much without -Werror. Often a technical linux user will want to download a source tarball for a particular version of a utility or program, and build it on or for a particular linux distro they're using. They usually do not want ad-hoc modifications done to the source of all the specific utility versions they compile for their system this way.