> This means, even if you're not using exceptions yourself, the compiler still needs to generate code to catch an exception after every function call, run all destructors in reverse order, and then rethrow the exception.

For every non-inlined function call (or one that it otherwise knows additional information about, e.g. with LTCG). For C++, this is a very big difference, since idiomatic C++ has a lot of inlined functions.