Enabling overcommit machine-wide is a puerile, broken approach that not only converts your server to an unreliable toy
Why should the reliability of your server matter (beyond a certain point)? For years Erlang developers have been following the "let it crash and a supervisor will restart it" model. They seem to have the uptime numbers to back them up.
Because erlang is also built around that concept. Often when a server fails it needs to be brought up by hand and then wait until it can be brought back into rotation (depending on how it's used &c).
Additionally, some applications, like a database often only run on a single host (sure you have hot spares, but fail over is often manual and recovering is defiantly manual).
So while I get your point, we're not going to throw out everything we have simply because it wasn't built around "let it fail".
Why should the reliability of your server matter (beyond a certain point)? For years Erlang developers have been following the "let it crash and a supervisor will restart it" model. They seem to have the uptime numbers to back them up.