If it's a BACKUP wallet, why the hell was it on the server anyway? Backup is supposed to be offline and only manual transfer when funds in the active pool get lower than 50%ish. That should be the most ever stolen +- a few % from like really recent deposits and such.
security is expensive.
It is unfeasible to host the site in house, since it would require a huge capital upfront.
Plugging on and off an hard disk from a hot swap bay in a datacenter roughly takes 30 minutes.
A premium datacenter (rackspace) charge roughly 350$ per hour in sensitive datacenters.
It's much cheaper to do this remotely.