Wasting peoples time is a relatively minor harm (in this one case - at scale the waste and diminishment of attention is an enormous issue). Increasing noise to signal ration in online discussions, cultivating a bot net that can be replicated or directly used for nefarious purposes, actively distracting from useful information and authentic relationships, and literally advocating for increasing utility zero spam are all bigger issues.

I think parent's objection is to exactly this logic - a sort of mental laziness demanding proof before willingness to attempt to grok the potential harm.

And then we get stuff like accounts hacked, bank accounts wiped out, people's lives/reputations ruined (social media, poor sec practices, etc.).

There are always consequences, just because it's cool and Shiney doesn't make it otherwise.