> There is no way you could do better, and it is unlikely that if you are building anything that needs more than a handful of servers you could build anything more reliable.

I can't disagree, but there is one key benefit to not using the cloud for some services.

When your company is working on an important deadline, your sysadmins could choose not to implement that pending network configuration change during that crucial period. You can control your own at-risk times, which you can't generally do with IaaS.

As with everything, it's a trade off.