The macro package should not be used as a substitute for normal R variables and conditions. In general, the R macro facility should be used sparingly. There are only a few scenarios when the R macro facility is advantageous.
The primary scenario macro package was written for is code generation. In this scenario, macro capability allows you to easily produce a resolved code file that can be saved and run independently. It is easier to produce such a resolved program using a macro language than alternative methods.
The other scenario the macro package may be useful is for translation of programs from SAS. The R macro syntax can be translated quite directly from SAS, without having to rethink the logic.
Outside of these two scenarios, using R macros must be carefully considered. Macros can introduce unnecessary complexity and make your code harder to debug. Please do not use the macro package as an excuse to avoid learning R.