It's not valid. You went to a page. They said "no, you're actually on the feed," and then immediately navigate you to the page you'd actually intended to visit. This is that they're doing today, and it's terrible. If I go to a URL, I'm NOT going to your homepage feed. I never wanted to go there.
Well, a lot of content, these days, is really data presented in a “window.” You don’t have the old HTML address, anymore.
It’s like reading an eBook in a reader. You always use the reader to interpret, format, and present the data.
It kind of sticks a spike into the old “each page is a document” model.
The experience you're describing still doesn't need to break the back button. Going back means going back, not closing a window I never opened. If that's an awkward experience, don't build one that works that way.
Fair ‘nuff, and I agree, but would they be able to argue that they never explicitly “broke” the back button?
I remember when JavaScript became a big Web site driver. The arguments against using it to fetch and build content usually included broken back button functionality.
I don’t think a lot of folks really paid much attention to it, though.