More importantly, standard procedure is also to keep multiple backup copies of important data. Because no matter who manages the infrastructure, the only reason the kill switch exists in a corporate environment is because there are scenarios where you plan to use it. Not to mention the very finite lifespan of all forms of modern mass storage, the relative ease of accidental deletion in most file systems, and so on.
For every person who loses "irreplaceable" data to malice, many more lose it out of simple incompetence.
Oh, sure, but I still thnk striking down with great vengeance and furious anger upon those who remote-wiped your devices would be justified, even with backups. If nothing else, it costs time to restore from backup, but if you were on a trip or something and had no convenient high-speed access to backups, it would be quite unpleasant. Especially if you had, say, iPad iPhone MBA, and assumed at least one of them would be likely to survive the trip, and thus had no other local backups with you.
But yes, backups -- and not just online backups, but also offline backups.
For every person who loses "irreplaceable" data to malice, many more lose it out of simple incompetence.