Incentivizing anything can lead to unwanted consequences. Even virtuous things such as reducing code.
This for me is a bad idea. I always have it in the back of my mind about reducing a modules footprint but as someone else mentioned on here. There's an art to it. Sometimes it's a bodge, followed by another fix in another part of the code base a month later which then frees you to delete.
Quite often it's like that actually. Patience is key.
I'd also like to add +1 for duplicating code. I see lot of devs just unwilling to dupe code at the cost of readability and speed of development.
Perhaps that code could be refactored down the line or more often the act of making it "neat" gives up 1 or more niceties that made you write it like that in the first place.