I notice that people who bring up shell scripts or makefiles in these types of discussions tend to tout the virtues of their setup based on those alone—putting

I notice that people who bring up shell scripts or makefiles in these types of discussions tend to tout the virtues of their setup based on those alone—putting undue focus on the glue layer, instead of the parts doing the heavy lifting—and this behavior strikes me as very odd. Shell scripts are only as stable as the executables that they invoke (and portability is a separate matter worth taking into account, too—few people who mention stability address the issue of incompatible variations of shell and make across different systems). In this case, the upper bound is determined by peg-multimarkdown that you depend on.