What it really says is how important washing your hands and disinfecting things is right now. This thing sticks around. Maybe not for 17 days in all cases...but long enough.
Also, just to try to keep the optimism alive...all they did was detect the presence of Covid on those surfaces...we don't know if it's still viable for transmission after those 17 days. Other studies suggest that the virus only remains viable for up to 5 days...which is still not great for us...but less than 1/3 as bad :P.