Because it's often claimed than Emacs can do everything. Or, if not claimed, than assumed. And if not assumed, people go and try to do this stuff anyway. I gave an example of an object-oriented spreadsheet in my article.

You can't stop people from trying, but that's just the wrong paradigm to try those things. My point: we can still have an environment that can do all of these things. Embed a spreadsheet and interface a database textually. Why, is what emacs giving us really the end of it, you think? Because I don't.

You must have misread those claims.

Yeah, right : D

In any case: there are quite obvious limitations, and, to me, they weren't very apparent when I started out in Emacs.