While the design of the device doesn't excuse user error, devices can, and should, be designed to minimize the likelyhood of user error (perhaps you can't close the storage case when the battery is removed) and the impact should an error still occur (cheap replacement batteries, available everywhere).

That's why car brake and gas pedals locations are not placed at the whim of the manufacturer.

This has to be weighed against other considerations (there is no room for a cheap, replaceable batter in an iPod Nono). (Edit: Freudian slip?)

I'm generally not a fan of rechargable batteries that have a proprietary form factor.