To add to the debate, there’s also the fact that Treasures have historically been, well, Treasure. They were generally precious metals, gems, jewelry, or other generally valuable items or money-alternatives. Cage and Gondola are a bit of a stretch in my mind for that reason, but then I thought about it more and Quarry has been around forever and doesn’t really meet the definition above either.
Anyways, the Treasures are cool. Getting to do a lot of Action-type things in your Buy phase feels great. Just played a game where I bought nothing but Silver Mines, King’s Cache and Crucible, and it was wild.