Eliza and direct text input in games

Once a tutor of mine wondered why there weren´t more experimentations with direct text input in games (that was before Façade, I believe), and why so few games tried to develop something like Eliza. I guess that´s because graphics got all the attention in games. Would there be any other reasons?

For you who don´t know what I´m talking about, here´s a description from Wikipedia:

"ELIZA is a computer program by Joseph Weizenbaum, designed in 1966, which parodied a Rogerian therapist, largely by rephrasing many of the patient's statements as questions and posing them to the patient. Thus, for example, the response to "My head hurts" might be "Why do you say your head hurts?" The response to "My mother hates me" might be "Who else in your family hates you?" ELIZA was named after Eliza Doolittle, a working-class character in George Bernard Shaw's play Pygmalion, who is taught to speak with an upper class accent."

For you who want to try it, here´s a web implementation.