I agree. And I don't know why there is this sudden hysteria about the problem. SAFARI HAS ALWAYS BEEN LIKE THIS!!! I like very many things about Safari but I've always hated the way that a Go Back reloads a webpage, unlike Firefox, or just about any other browser, which return you instantly to the page as it was, from the cache.
There is one way to confirm this problem : go to a site that you know changes every day (e.g. a newspaper or a daily word game or something). Go to that site in both Safari and Firefox. Next day, launch both browsers and observe...
Safari will load TODAY'S page not yesterday's -
Firefox will load YESTERDAY'S page.
This is how Safari seems to work. It always reloads web pages when you do a Go Back. It's infuriating but it seems to be part of the design.