[sordina]

There may be a bunch of other reasons, but the one that springs to mind is localisation of errors. You'd ideally like to know about any mistakes you've made in your macro before you run your macro. And when you do learn about a mistake you'd like the error to describe where the mistake is in macro-land rather than generated-code land.

[junke]

Why just type errors? You might want to trace any error that occurs at runtime back to the original source code anyway.

[sordina]

I agree, you may wish to do that but I was answering the question "What is the utility of typed-templates", not "contrast type and runtime error tradeoffs".