Many projects are managed by features. This makes sense as customers
pay for and track features, people work on features, features are
tested and integrated. 

Unfortunately quality is often not considered a feature. Improving the
system is frowned upon because it is risky. Work related to features
is ok, but work on related to quality is not. Therefor the system
does not improve. It may degrade because there is emphasis placed
on changes the don't cut across the system and that change the fewest
files.

Quality is a feature. Have a quality feature in every release or your
system is degrading.