I agree with you. I just want to say, the live-code facet of the demo is great, and I think it supports some of what Bret Victor has been advocating about providing immediate feedback. However, a large part of it looked like just another programming language where the environment required a lot of mouse-clicks to do simple things, such as get some basic math in to the equations. Personally, I don't want to program using pictographs.
Part of programming is communicating thoughts. Plain text is great for that - we all read and write text. I also think it's easier to type "sqrt" or "sum", than to right-click, scroll through a pop-up menu and select the symbol I want. I suppose symbols can help one verify they've written what they intended if the environment supports translating "sqrt" and other functions into symbols that stretch over and around variables and other equations, but that's not what was demonstrated.
Finally, as others have pointed out, the mathematical expression of an algorithm doesn't necessarily lead to an efficient one.
Part of programming is communicating thoughts. Plain text is great for that - we all read and write text. I also think it's easier to type "sqrt" or "sum", than to right-click, scroll through a pop-up menu and select the symbol I want. I suppose symbols can help one verify they've written what they intended if the environment supports translating "sqrt" and other functions into symbols that stretch over and around variables and other equations, but that's not what was demonstrated.
Finally, as others have pointed out, the mathematical expression of an algorithm doesn't necessarily lead to an efficient one.