Longstanding OpenStreetMap principals include

1. Do correct errors -> https://wiki.openstreetmap.org/wiki/Good_practice#Do_correct_errors

2. Don't remove objects that you don't need or like -> https://wiki.openstreetmap.org/wiki/Good_practice#Don't_remove_objects_that_you_don't_need_or_like

In this case, the these existing building features are reasonable, and in my view they are pretty good. If you don't agree you're welcome to improve them, but don't delete others work just because you don't like it.

We'll revert this change, please avoid this going forward.