New Coke, the Mustang II, the Apple Newton.
There may be an interesting case study here regarding the system development process and what happens when it is not done properly.
Somehow the requirements for 'good navigation', 'marking items as helpful', and even 'finding things you posted' were lost, mistranslated, or ignored.
I don't know what happens behind the scenes at TR, and this is not intended to be a slight or criticism of them....they do seem like a nice group of people.
However to call this change a train-wreck is an insult to train wrecks.
I am guessing that the new site is some sort of content-management system that just 'works this way', therefore they are stuck with it, while I am guessing that the old site was a messy homegrown system that was horribly complex and hard to maintain....but worked.