It wouldn't be desirable in a lot of cases for the reason the other person mentioned. I don't believe you should have to write your own parser mind you, just that your compiler's parser may not be the one you want.

In general, most languages are stable enough that you don't really get parsing/semantics bugs, so you wouldn't really need to worry about your last concern.

C++ is simply so complicated that the implementations end up with a bugs due to necessary complexity of implementation, but this is not generally true of languages.