because booleans will mess up the topology.
the shape is easy enough, so you shouldnt need any booleaning anyway..
quick example of how to do it using just the connect and chamfer tools
if you did that with a boolean, you'd have to dismantle most of it anyway and rebuild it in order for turbosmooth to work with it.
you might have to clean up some of the loose support loops in order to get the shape in your ref.