I agree with you on this one, but except for one thing. The walls are too thin to have your own space. It's quite uncomfortable that you don't have your privacy even you're at home.
If you are talking about walls within your home, that may be true, my living situation was such that I wouldn't know. If you are talking about thin walls between neighboring apartments, I never had much of an issue. Perhaps they are thing, but in general Japanese people are so conscious of others that I never had an issue with loud neighbors.