I think the reason is that text is already a highly optimized visual way to represent information. It started with cave paintings and evolved to what it is now.
"Please go to the supermarket and get two bottles of beer. If you see Joe, tell him we are having a party in my house at 6 tomorrow."
It took me a few seconds to write that. Imagine I had to paint it.
"Please go to the supermarket and get two bottles of beer. If you see Joe, tell him we are having a party in my house at 6 tomorrow."
It took me a few seconds to write that. Imagine I had to paint it.