Perhaps I am not referring to the correct technology/feature if you find it so confusing? In my post all I was trying to say is that enabling writing code that generates predicates, expressions etc, literally syntactical building blocks of more code - via code in an inception-like manner - seems to be at least equally complex an endeavor as somewhat arguably non-trivial matter of creating or using python-like AOP decorator “proxies”. So presence of Roslyn kind of disproves that the emphasis on simplicity is still in effect, at least in my mind. Hope that clears up my point.