Change a Managed Solution to Unmanaged in MS CRM 2011

You can export a solution in MS CRM 2011 as either managed or un-managed solution. If you export a solution as managed you cannot do any customizations on that managed solution where ever you import. This is mainly for ISV’s to protect their code.
But I think we can covert a managed solution to unmanaged solution quite easily. Check the below procedure.
  1. Export a solution as managed
  2. It will create a zip file with three files: [Content_Types].xml, customizations.xml, solution.xml
  3. Extract the zip file and edit the solution.xml file.
  4. Find the <Managed> attribute in the xml file. This will have value 1 for managed. Change this to 0. Your final value will be <Managed>0</Managed>.
  5. Zip the three files again and import to new organization and solution is unmanaged.
Am I doing something wrong here??? Can’t I stop a user to import my solution as unmanaged???