The system wasn't designed with that consideration in mind, locking mechanisms can break when you do this and don't know that the folder is in use by another sy

The system wasn't designed with that consideration in mind, locking mechanisms can break when you do this and don't know that the folder is in use by another system (functionality varies per OS). If you are moving files to reorganize structure of a project, the .svn folders will cause conflicts, and you'll also loose the history of the move, (instead a continuous history of that structure, it'll appear as a new structure) Lastly, when supporting my developer pool with SVN, resolving corrupted .svn folders because of moving folders in correctly is a time consuming procedure and usually ends with an export command to kill all the .svn files, and risking blowing away changes in with a commit that ignores history.