Why is LastPass Pocket not recommended? [closed]

From the lastpass site:

"LastPass Pocket is a stand-alone application (available for Windows, Mac OS X and Linux) that can be installed on a USB memory device, allowing you to carry your LastPass data around with you. Pocket essentially provides backup capability and offline access for your Vault, although we recommend LastPass Portable over Pocket."

Why? Because you are carrying the entire password that is encrypted with you on Pocket. I.E. If you lose this, some hacker could determine your key by brute force and since this is a safe full of passwords, you are now vulnerable.

On portable, passwords are still resident on the server, thus if you lose the USB you have this program on, you do not have to worry that you are losing a copy of your total password database.

Seems to make sense to me.