His solution "keep it on a local machine" is just as bad advice (at least for most people). What if your hdd crashes? Do you make backups? After every send? Are they stored safe enough or can other people find it there? Do you encrypt it? What if you lose the key?
And so on. This is a hard problem.
Most solutions that work against loss do not work against theft, and vice verse.
This is just wrong, wrong and wrong some more.
You only really need one to two backups. Both encrypted with a secure password. One backup can be stored on site and one backup should be stored off site. As long as you use common sense in choosing your password (passphrase) for encryption and use a suitable encryption mechanism; I suggest Truecrypt or 7zip. You are adequately protected from everything but a major disaster of proportions that will make Bitcoin the least of your worries. As long as it's adequately encrypted, you do not have to worry about it being stolen.
You do not need to make a backup after every send, that is just ludicrous. Maybe every 75 or 100 sends or perhaps once a week at most unless you are really active. Regardless, it's not the sends you are concerned with but the receives. It's the other people job that you are sending to to back up their wallets to protect those transactions.