I see where you're coming from. However, let's look at it this way. When I click on a thread, it'll bring me to the first page. To go to the "last read post" tab, I have to scroll all the way to the bottom.
This is not a big deal, but it can be a bit of a pain if you have to do it multiple times a day, day after day.
In regards to Google, the main purpose for its page is to show the results of a search. More often than not, people will search using different term, which in turn will produce different results. One would want to scroll through those results. However, on a thread, the person has already read/scanned the first page on the initial visit. Anytime after that, that importance of that first page becomes irrelevant.
Regardless, I think this new layout is going to turn out to be amazing with a few tweaks. It's very innovative and is getting "cleaner" by the day. I wasn't the biggest of fan initially, but it's starting to stick.
