"Seriously???!!! "
Yes.
" I just bought a $14.99 movie and can only watch it on my computer?"
No. You can connect your computer to any TV with inputs and watch it there. You can watch it on Apple TV, ipod, ipad, iphone also.
You simply cannot burn it to disk and watch it in a dvvd player.
Just as you can ONLY watch a dvd on a dvd player. You cannot watch it on an ipod/iphone/ipad/Apple TV and you cannot watch a dvd on any tv that does not have a dvd player.
From the itunes store terms of service:
"You shall not be entitled to burn video iTunes Products"
http://www.apple.com/legal/itunes/us/terms.html#SERVICE