I'm not sure if the situation has changed, but I recall installing Fedora (and another distro I cannot recall) years ago, and SELinux would kill sshd when a connection was received, on a clean, out-of-the-box installation, making the host inaccessible.

These sort of super-critical bug make software go immediately into my blacklist, and it's very hard to come back from that - it basically meant that it had to be disabled immediately, because it's defaults were completely broken.