I don't know about templating, but... is Haskell's Hindley-Milner type identification system Turing complete? For that matter, Lisp's macros are definitely Turing complete, and they are... a templating system on steroids, maybe?

About mindshare: Lisp has zealots, but they are few, even if they are loud, and they are on HN more than many other places. C++ is perhaps not loved, but in some circles it is very well respected, the way a chef respects a very sharp knife. The value lies precisely in the sharpness.