Every time I see a couple oohing and aaahing over a gigantic master bedroom and its palatial ensuite bath, I can't help but think, "Blah, just more space to clean. No thank you." Unless these people really love cleaning. Or maybe they hire someone to do their cleaning for them? Me, I'd much rather have a small-but-perfectly-functional bathroom that takes much less time to clean!
Of course, the first house I remember from when I was growing up didn't even have a master bedroom with an ensuite bath. One shower for everybody (though we did have another half bath downstairs). Then we moved to a new state and our new house had an ensuite in the master bedroom, but my parents never really treated it like it was their own private bathroom. We were five people with two bathrooms, to be split however was most practical at the moment, and one of the bathrooms just happened to be off of a bedroom. I remember sometimes I'd have friends over and if the front bathroom was occupied and someone else needed to go, I'd tell them they were welcome to use the one in my parents' bedroom at the end of the hall. I would get these horrified looks in reply. I didn't get it; to me, I thought, "It's just a bedroom, and they're not in there at the moment, so...? It's okay, I promise! They don't care!" One of those things where it takes you awhile to realize that not everyone thinks the same thing is "normal"!