It stops being a feature and becomes a bug bordering on retardation when they purposefully ship broken software.

First example coming to mind, TLS is broken in the version of OpenSMTPD that ships with Debian Stable.

Yes you read that correctly.

The version of OpenSMTPD in Debian Stable does not have functioning TLS. It's also not well documented why this is, things just don't work and you are forced to discover why.

It has to do with a broken dependency on their ancient version of OpenSSL. They refuse to patch it because muh stability - it requires a version jump. So you are forced to jump through hoops and install a newer version from backports if you expect TLS to work on your SMTP server.