Although many X-ers are now going for the McMansion thing, it was definitely a Boomer invention. I live in a typical (small, semi tacky) typical post war house favored by the parents of the Boomers. It is like a different planet from where most Boomers live.
I know what you mean; the house we remodeled was built in 1964, so it's like the houses a lot of us "boomers" grew up in. My husband and I added on because we felt we barely fit into the house, and yet I know our parent's generation probably raised three or four kids there.
Friends of ours - just a couple, no kids - just moved into a house that is 6600+ square feet; it's amazing. The wife's walk-in closet and the storage space behind it are about the size of my first post-college apartment in Boston. :-\