I've been looking around the web at reviews and analyses of Jetpack, and I haven't been able to find any coherent discussion surrounding why not to use the Jetpack other than avoiding Wordpress.com's Terms of Services (which is unfortunately mandatory, even though Jetpack contains some plugin code that does not require Wordpress.com services or an API key).
A secondary question is: what is business motivation behind Jetpack? Is the idea to bring more WP usage data into wp.com's usage, giving more data to shape the product? Is it merely the delivery of freemium services like VaultPress?
Thanks for any answers!