Good point in general, but, what they’re specifically talking about here (rolling codes), perhaps what they should have said is that no one can (feasibly) do it, not just that their hardware isn’t capable.

Edit: Oh, for the blocking signal, that part might be functionality that could be added, I see what I think you’re saying there. Still, that would be a step towards it, but it would still require serious hardware to crack a private key, as I understand.