This is probably very context dependent, because I've learned the opposite. For example, I was rewriting/consolidating a corner of the local search logic for G

This is probably very context dependent, because I've learned the opposite. For example, I was rewriting/consolidating a corner of the local search logic for Google that was spread throughout multiple servers in the stack. Some of the implementation decisions were clearly made because of the convenience of doing so in a particular server. But when consolidating the code into a single server, the data structures and partial results available were not the same, so re-producing the exact same logic and behavior would have been hard. Realizing which parts of the initial implementation were there because it was convenient, and which were there for product concerns let me implement something much simpler that still satisfied the product demands, even if the output was not bitwise identical.