If I came into work today and brought up the idea of doing a complete code rewrite, I'd either get laughed out of the room, or even worse, threatened with being fired
If that's really the case, then you're working with a bunch of abusive, pedantic, and narrow-sighted assholes. I will generally say "no" to the idea of a complete code rewrite of any meaningful and currently useful system (based on my own experience as much as Joel's article), but I won't laugh at people or threaten to fire them over it.