Among reasons, I see stuff like this: "Appearantly someone set the connection timeout to 9000 secs which means a connection to a MongoDB instance through Netscaler is open for 2.5 hours. I have set it to 20 secs. I am not looking for someone to blame but probably it's our sys admin.

Wouldn't any database give you plain bad performance if settings were badly configured? I understand it was merely one of the reasons, but sometimes all you need is one.