“Make those parts pluggable/replaceable which would be a good design anyways”.

Following best practices = Morally Wrong?
Sure, fren, whatever you say.

The only reason OP might not have done it this way in the first place would have been to save the company worrying about licensing, or getting shitty with OP about not using enough orignal/proprietary code to ensure lock-in with future clients … is THAT somehow morally superior in your book.