I feel like this is a deliberately obtuse response to a real and irritating change.

Old reddit is going to be MUCH, MUCH easier to scrape. Scraping has the potential to bring down the site. Gating old reddit to logged in users will massively mitigate that.

I don't like it either. But it's not hard to see a good reason why doing so helps "keep reddit safe"

Even if it also coincidentally makes it easier for them to make more money. Grr.