Visual languages have been superseded by abstract symbolic languages time and again throughout history. I don't really feel qualified to determine whether or not visual general purpose programming languages could work or not, but I do think that anyone who is pursuing that goal needs to start by figuring out why natural languages progressed from visual to symbolic. Demonstrating that programming languages could progress in the other direction would probably be the primary goal of their endeavour, and when they present their work, it should probably focus on examples of idioms that are easy to express visually, but difficult to express in text form. I am not convinced that those idioms even exist; but then, since I have never used a visual programming language. It could be that I am simply incapable of contemplating them, in my current frame of mind.
