The truth, I think, is that the use of computers can go either way. More sophisticated research computers at the universities are used to study pictures of Vietnamese jungles to help figure out where to drop the napalm. If students do use the computers, it is often only for teacher-directed drill and practice, no matter how cleverly disguised as a game. Better uses of the technology are possible, but they aren't inevitable. Consider an analogy.
Most teachers probably agree, in principle, with the idea of educational freedom.
Students learn best through intrinsic motivation, not through force. What you learn under pressure doesn't last past the exam. Everyone says these things, and yet almost all teachers continue to give grades. The same political reasons make educational freedom through computers a difficult goal. Remember, many school computers are funded through federal grants, and the feds always insist on evaluation of the program.