Earlier quoted context omitted.
It wasn't actually due to the actions of their user though, was it? It was because of the actions of NoIP themselves, who did not act to prevent abuse by their users. From what Cisco and Microsoft are reporting NoIP is (was?) a hotspot of botnet activity. If NoIP was not doing anything against that Microsoft's lawsuit doesn't sound that unreasonable. How this was actually implemented in the end (MS just taking over t…
You might just as well say it is the IANA's fault for issuing the IP addresses the malware authors used, or Ford's fault for building the getaway car used in a bank robbery.
Turning over IANA or Ford over to Microsoft would not prevent malware or robberies. Turning over NoIP to Microsoft will prevent malware (at least in the short term).