I think a reason for this phenomenon is that removal of something generally requires an understanding of the intent and behaviors of the system as it is (and be

I think a reason for this phenomenon is that removal of something generally requires an understanding of the intent and behaviors of the system as it is (and better yet, why it was built that way, and what levers you have available to you to modify it, or constraints that you cannot change). Much easier (or takes less thought, or more easily glosses over important complex unappreciated issues) just to add something that you think will solve the individual problem at hand...