Pretty much "everything" (other than public domain) on the IA is on shaky ground. It's been mostly OK because very few people object to the archiving of their public web pages (especially given the IA respects robots.txt even retroactively) and, as you say, old magazines that basically have zero commercial value.
IA stopped respecting robots.txt in 2017. I had to issue a DCMA takedown to get my sites delisted. They are arrogant and think themselves above normal netiquette. They deserve to lose.
If anyone is arrogant it's those that think they can make information publicly available but then still control where it is shared.
You don't get to define "netiquette" to whatever you want it to be.
robots.txt in particular has been a giant mistake that only seves to entrench Google. Anyone that wants to archive or index the web as it appears to humans SHOULD ignore it.
