Operators making reckless choices like that, especially when DNSSEC is barely being used, does not invalidate the technology. And it would also not have impacted DNSSEC used for DANE as the client would be verifying the DNSSEC chain in that case and not just the recursive resolver. But don't let that stop your eternal butthurt about DNSSEC. Whatever issues DNSSEC might have, at least its not broken by design like the current web PKI where we have hundreds single point of failures.