Arduino IDE deletes entire contents of build.path directory

I set my build.path directory to my C:\Users\\Downloads folder, so that I could conveniently retrieve the .hex files if needed (There was a week-long period where the only AVR programmer I had was a cheap Chinese thing that used a proprietary program, and I needed the .hex files in a convenient spot to send via that). Unfortunately, I did not realize that Arduino IDE occasionally deletes the entire contents of its build path, and I lost the entirety of my Download folder's contents (which contained many, many, many non-Arduino files., including photographs, memes, old projects, etc., many of which were not backed up).

Can there either be:
1.) A smarter delete routine for the files in the build path so that it doesn't clear out any unrelated files, or:
2.) A huge warning to set your build path in a dedicated directory not shared with any other files.

(edit- fixed several typos)

Start by reproducing the build.path cleanup behavior in Arduino IDE 1.x using a directory that contains both build artifacts and unrelated files. Read the build-path handling and cleanup entry points, then verify that cleanup either preserves unrelated files or clearly warns users before deleting them.

Written by the indexing model from the issue text.