Regarding @/AltTextHealthCheck@mastodon.social results at any given time:
I'm all for calling each other in and/or out in order to increase accessibility.
But you know what?
Not only have I worked with a lot of professors who don't know the basics of alt text or textual equivalents, but I've also worked with a lot of academic librarians who treat it as somehow highly specialized arcane magick and also somehow beneath them.
These are people with advanced degrees. Knowledge workers, some of whom are also specifically information workers whose library degree almost certainly involved direct instruction about this at some point.
Clown on specific instances if you think it'll be productive.
But we all can do better when it comes to alt text and other simple steps toward #accessibility, both online and off.