> Reusing a function C in functions A and B makes A and B dependent on C. If the definition of C changes, the definitions of A and B also change. To pile onto

> Reusing a function C in functions A and B makes A and B dependent on C. If the definition of C changes, the definitions of A and B also change. To pile onto this example, in some cases the mastermind behind these blind deduplication changes doesn't notice that the somewhat similar code blocks reside in entirely different modules. Refactoring these code blocks into a shared function ends up introducing a build time dependency where previously there was none, and as a result at best your project takes longer to build because independent modules are now directly dependent or at worsr you just introduced cyclic dependencies.