Deleting all the post of a member doesn't affect only that member but all the community when said member has been involved in the rp scene for quite a while.
This is just a lazy way of pressing one button to remove all posts without dealing with the specific problem.
So why?
Are you trying to set an example out of him just so none else does what he did knowing the risks from this point forward?
and another question:
What did he do so wrong to deserve this while the others were not treated the same?