Is there a motor home expert out there?

I don't know why I was looking at them, but a recent browse of motor homes and trailers revealed that manufacturers try to cram as much sleeping space into them as possible, at the expense of everything else. I understand that there's a market for that, but what about couples who want to travel in something bigger than a van? The larger you go, the more sleeping space there is, while everything else stays relatively tiny. Why can't they make big motor homes designed for 2 people? One big bedroom, one big kitchen / living room. A bathroom you can turn around in. A shower that is elbow-friendly. Is that too much to ask?

Of course, I may be naive and have no clue what I'm talking about, so feel free to steer me straight if that's the case. Include details.