I find the trick is to do maintenance while doing meaningful (as described by the powers that be) work. So when a new feature or bug fix is asked for, add another 15% to the time required, and clean up the code base a bit.

The knee-jerk, which rarely works, is to demand time to refactor everything or ignore everything until it breaks irreparably.

I think in your case, simplifying a script by a dozen lines a week or so could have been done without taking away "points". Abandoning the status quo and committing too much time will inevitably be looked down on in most industries, however.