No, the Japanese do not need to be less superficial. If Japanese want to visit a museum for rocks with faces, then they have the right to open a museum for rocks with faces. There are many museums all over the world - some are more serious then others - this Japanese museum has a right to be open too.
Japanese museum for rocks with faces: the Japanese do need to be less superficial and concentrate on more serious issues. Really, whose business is it to decide what is or is not superficial? Time for the whiners and complainers to find something less superficial to worry about and concentrate on more serious issues.
Americans certainly don't have any business criticizing other countries for doing ridiculous things. Americans are the best at coming up with silly things to spend time and money on. If the Japanese want to call this art and come up with a museum for it, more power to them. They can do what they want.
The Japanese have a deep reverence for culture and this is something the rest of the world can learn. Economic, health, safety and environmental issues are just as important as culture when it comes to keeping a population happy. I don't think any museum can ever be frivolous unless it engages in propaganda.