Your reaction is very similar to the reaction people who have never used Python have when they discover Python has significant whitespace (with no vested interest against Python): "That's a horrible idea! It failed miserably for Fortran 40 years ago! That goes against everything I was taught!". Yes, it does not fit exactly with some mental model you already have. But no, it does not set up false expectations, much like Python does not set up false expectations of whitespace significance for C programmers who wrote a couple of Python programs.
Anthony already addressed the details in his reply below, but let me just add: IPython and sage essentially redo the python command line, and get nothing but praise. web2py, in some limited contexts (models and controllers) introduces a few useful names into the global namespace, and gets a ton of criticism.
Django (and just about every other framework) introduces a whole new language for templates, and no one squeaks, wheresa web2py uses plain Python as its template language with the smallest modification possible to provide that (you need to add "pass" at the end of a block, because you don't have indentation to guide you properly inside an html template; other template languages add an "endif" one way or another), and no one cares.
It is telling that all this criticism is coming from people who never use web2py, much like criticism of significant whitespace comes from people who do not use Python.
It is bigotry, disguised as a technical argument. In both cases.