We apologize for any frustration this has caused. Simply removing the game yourself will not reset the data associated with your Steam account and your Stronghold Kingdoms account. Only Steam is able to remove a product (in this case Stronghold Kingdoms) from your Steam Library and reset the data associated with your Steam account and a product. This is the only way to unlink your Stronghold Kingdoms account with your Steam account and must be performed by Steam.
We hope that Steam Support will be able to resolve this issue with your Steam Library to your satisfaction and hope that you continue to enjoy Stronghold Kingdoms!