The thing is, hardware manufacturers might be all for something like this - if it means they can increase their market from x embedded developers to 100 times more web developers. They are already trying to make embedded development drag and drop - an example is this tool by Infineon called 'DAVE' - not sure how successful it is, but its built around modular components that you drop into your project.
This sort of thing breaks the very moment you have to bring in your own customizations and changes. And that is super common in a embedded system.
Otherwise it wouldn't be much of an 'embedded system'. It would be a general computer.
Drag and Drop code generation doesn't work in embedded programming for the very same reasons it doesn't work with higher level languages. Its far too inefficient,code subject to total redesign for small changes in feature requests and beyond all its not economical.
Some day we may get there. But some day we may not even have the need to program anything. Forget embedded systems, but programming in general.
http://www.infineon.com/cms/en/product/microcontrollers/deve...
Of course its all written in C, but you get the idea.