Housing can’t both be a good investment and be affordable
A lot of people here are playing semantics and ignoring the message of the article just to be "clever".  The message of the article is we can't have our "housing values are always increasing" cake and eat our "housing is always affordable" dream too.  If we want to keep housing affordable, we'll have to settle for valuations staying pretty much constant in real dollars forever and resign ourselves to be happy with only the savings opportunities everyone here are so cleverly pointing out.