Not many industries can afford refactoring of the code is not supposed to be changed - additional (unexpected) regression testing costs, risk of downtime, etc. You learn that if it works and is in production - don't touch it.
Which is greater? The cost of refactoring or the cost of not refactoring? If the consequence of not refactoring is having to deploy twice as many services and libraries every time you add a feature... that sounds pretty risky to me over time.
