I wouldn't have a problem with it, if the implication wasn't that the author became smarter as a result of reading this code. That's my whole beef with it.
'Hey, look at this interesting way of using the CPP to create a DSL'
I'm fine with that. But this is precisely what aspiring C programmers should avoid at all costs. It's not controversial. It's bad.
Still, since the article already contains this warning, some people might argue that it's unnecessary for us to add it as a response to every comment here.