I'm not sure about other compilers, but I use gcc. Mild errors in templates can produce reams of errors, the first of which might have a good hint, and if not, the actual error is tucked away in, perhaps, the third attempted template substitution. This is a very valid concern. Good error messages are hard to produce, and gcc doesn't even try to figure out which brackets are mismatched.

Mix that in with a supercharged comptime constructions, and I'm quite terrified. I don't have these issues with macros anymore, thanks to templates, but I nearly prefer them.