In some sense, it might not matter. If an ASN/company admin responds to emails in a hostile fashion, does it matter if they bought their devices in good faith? They're still assholes.
Hostility can often come from a place of ignorance or misunderstanding. I can't say much for the former, but the latter can easily go wrong with the cultural and linguistic barrier between operators.
The guy operating the NOC may be a dick, but is taking down the IoT networks for all of their customers unknowingly relying on your services really the right way?
Personally, I'd say yes, it'd help. However, there's an argument to be made that the hostile ASN operator doesn't represent the people behind the network in the slightest. I can understand that someone may give such an asshat the benefit of doubt and drop it despite their abuse.
The guy operating the NOC may be a dick, but is taking down the IoT networks for all of their customers unknowingly relying on your services really the right way?
Personally, I'd say yes, it'd help. However, there's an argument to be made that the hostile ASN operator doesn't represent the people behind the network in the slightest. I can understand that someone may give such an asshat the benefit of doubt and drop it despite their abuse.