Other online tax preparation software doesn't really let you e-file this form. The form cannot be e-filed. Period. The IRS system has no electronic version of this form.
Some software allows you to attach documents to the e-filed return as allowed by the IRS, but that's not the same thing and is prone to error.
It's not ridiculous that TurboTax doesn't allow you to e-file a form that can't be e-filed per the IRS... goodness.
