I'm with you. I couldn't make gestures into something that was good for me. My current phone lacks physical buttons (except for power and volume up/down), and I've never stopped missing them -- it's my #1 complaint about the phone.

The android buttons in most cases these days are not hard buttons but soft ones that could just as likely change at the whim of Android, using your own hypothetical situation you came up with. They are cumbersome because usually it takes two hands to press them, as they are small buttons at the bottom. You end up needing one hand to hold the phone and the other to accurately press the button. With thumb-gestures, you can do it blindfolded in one hand. In addition, the buttons take up screen real estate.

Also, have you actually used the BlackBerry gestures? Upon getting a BlackBerry, the very first thing it does is a 1 minute tutorial explaining how to use the gestures. There are only a few. They really aren't complicated. They just take a brief explanation and the reward is you get a more functional interface.