I've a few publications out there and if I had to release my code I would. However the reason I don't instantly publish the code is because its kinda embarrassing. My code works and it has some level of unit test coverage to make sure numbers make sense etc. But the code itself has a number of inefficiencies or ridiculous variable names... or in some cases serious example of breaking DRY.
However if everyone had to publish their code, I know the elements of my code which cause me distress would be nothing compared to a variety of other implementations people create.
Oh also trying to reproduce someone else's algorithm from a paper is so painful. There are a number of experimental values that exist which aren't really mentioned in papers as they are deemed trivial so you've to do no amount of tinkering to get similar results.
However if everyone had to publish their code, I know the elements of my code which cause me distress would be nothing compared to a variety of other implementations people create.
Oh also trying to reproduce someone else's algorithm from a paper is so painful. There are a number of experimental values that exist which aren't really mentioned in papers as they are deemed trivial so you've to do no amount of tinkering to get similar results.