Sounds appealing, but I think in practice this would be very unpleasant to work with. ASTs are almost always significantly more verbose than the code that generated them which makes both reading and writing more painful.
I say this from my own experience designing a language. Writing the AST directly was at least 2x as long as the language code.
I agree with this if the AST is a YAML or JSON document, but maybe if it was visual then you wouldn't have that problem (but I imagine it would exacerbate the style problem while also eliminating many of the advantages of text formats).
I say this from my own experience designing a language. Writing the AST directly was at least 2x as long as the language code.