From doing that, you won't get a perfect IV Rotom.
If one of the parents holds the Destiny Knot then 5 IVs between both parents will be passed down.
As you can see, none of the parent's Attack IVs are perfect, hence the offspring is guaranteed to not have a genetically perfect Attack IV.
So, you won't get a perfect IV Rotom, but otherwise you're just unlucky. Just keep trying, you're doing everything right. :)
Hope I helped. :)