Carl brings to light what's wrong with the Update process. But in a way where as I believe it's bringing to light the more prevalent issue behind why WordPress has fully jumped into the plugin update process automatically. There are many people out there that aren't developing and using plugins in a way that fits with the best practices of WordPress. There's also many developers that tell their site owners to not perform updates because of this. Therefore if there's an update and things break, then that site owner thinks that WordPress broke their site. This is a practice that needs to be addressed and by WordPress fixing the update problem, it may rain on some of the market share initially, but propel the best practices of development and education for site owners forward.