There’s more here than just a vague fuzzy warm feeling that the code is ‘tight’. It means longer code-build-test cycles, more resource requirements from the code, and harder-to-solve optimization issues. Worst of all, replicated code means replicated bugs. It means developers are spending a lot of time doing the same work over and over again, with slightly different details. Slogging the same boring code over and over again is essentially menial labor, and is bad for morale.