Deleting anything given the limitations of Facebook, is very irresponsible. I've invested hours of commenting on stuff. The way Facebook is designed if people delete their comment or posts on which I commented, my content gets wiped out, too.

Other systems have handled this gracefully in the past. I hate when somebody decided to wipe all evidence out and put hours of life into the trashcan.

If you want Facebook to be responsible, set an example, and be responsible and respectful of other people's time and effort!