I have disabled it also. It is annoying when laying in bed and I turn to my side the screen will automatically rotates. Any games like Air Attack HD that are designed for the tablet to be vertical; it will automatically rotate the screen anyways. The only reason I could think of the use for vertical layout is for typing with your thumbs only.
I would strongly recommend buying Thumb Keyboard from the market. It is only 1.32 Euros and $1.87 US. It is so nice to type with my thumbs while holding the tablet landscape. I can type so fast when surfing the internet. It cuts the keyboard in half and moves the keys to the sides and has a 10 key number pad in the middle. Select 10 inch tablet mode in settings. Try it out. You have 15 minutes to test drive it and if you don't like it, uninstall it and get a full refund.