I've posted about this in other places on this thread, but after feeling the same way as you, I looked at some old movies, and found that most posts are fairly recent. It turns out that IMDB has been expiring posts all along.

Your argument is sound though. Comments on websites, even if filled with trolls and fakes ought to be treated with respect and saved for posterity, since they give an important insight into the current zeitgeist.

Oh, I don't know. I was a daily user of Usenet for years, but the vast majority of the time I don't miss it. (Yes, I know Google still has some unevenly preserved and mostly difficult to access portion of the content.)

Here's the point: if you put some of the great content that was created there 25 or 30 years ago in front of the current generation, what is the general reaction? A yawn, that's what.

It might be fascinating in a few thousand years, but I won't be around then, and the planet might not be either, so why should I care?

For a certain definition of "nice", possibly. It's a little bit of a depressing thought that some future culture might find only our online comments and study our culture through that.

What else should they find of our current culture? Our books are written on very cheap paper which will not survive the next 100 years.