The reason is they are not getting 'hacked'. Its jagex new strategy they wipe wealth off accounts and follow up with a delayed ban days later. They do this in hopes of more wealth being added to an account and getting banned and to remove wealth from the game in general. I know i wasn't hacked when this happened to me as i logged in on the exact same square only my gold farming items were gone and a few moderate items (100kish) were remaining