Often the reason can also be evolution. Where the code started off doing something specific - but then as it evolved, more features were added, approaches chang

Often the reason can also be evolution. Where the code started off doing something specific - but then as it evolved, more features were added, approaches changed, the code evolved to do something totally different. Also "starters" - people who are good with getting something shippable fast and iterating on features and not the same people as the ones that write truly great code - simply b/c they're driven by different things. But it's very situational.