Seems to me like the Internet Archive can determine for itself what it's job is, and they've determined that this is in fact part of their core mission.
Your perception that their purpose is solely to archive the Internet is at odds with their actual demonstrated activities for many years (the home page says: "Internet Archive is a non-profit library of millions of free books, movies, software, music, websites, and more"), as well as their public mission statement: "Our mission is to provide Universal Access to All Knowledge."
I've talked to the founder of the IA who told me he doesn't believe the lawsuit puts the IA at risk of having to shut down.
They can, but that doesn't mean they are right. Controlled Digital Lending is not an "obvious" mistake, and contrary to what people on HN keep saying, the emergency library program is not what this case is about. It also does it seem to be the situation that their entire mission is at risk.
Your perception that their purpose is solely to archive the Internet is at odds with their actual demonstrated activities for many years (the home page says: "Internet Archive is a non-profit library of millions of free books, movies, software, music, websites, and more"), as well as their public mission statement: "Our mission is to provide Universal Access to All Knowledge."
I've talked to the founder of the IA who told me he doesn't believe the lawsuit puts the IA at risk of having to shut down.