My work is done almost 100% at a desk, in different rooms of my home depending on the season (some get too cold or too hot) or on a whim. A desktop won't do. And sometimes I really take my laptop to somewhere else.
Different strokes for different folks and all, but it's hard for me to imagine this. I have 3 large monitors, so even if I had a laptop I would want to move those around as well.
After working with large monitors, I don't know how anyone gets serious work done on a laptop screen.
I do have a laptop, but it is relatively inexpensive and used mostly as a thin client to my desktop (as others have mentioned).
Edit: I will also add, I like having a dedicated space for work. This prevents work from creeping into my life everywhere in my house. I can't be on the couch, watching a movie, and have the urge to work - I'm not in my work space!
I mostly agree with you, in that I usually find working on only a laptop screen frustrating and love having a dedicated work area.
But it depends on the task I do. For example, I quite enjoy working from my parents' garden when it's nice outside and if I do some focused work. Like reading some "long-form documentation" (where I don't need to follow it along as I apply it) or when I do some routine sysadmin work.
I have a big monitor (don't like having multiple monitors) at my parents' house, with a dedicated desk in a "work area". I also have this at home. And I also have this at the office. It's much more comfortable to move around these locations with a laptop than it would be to haul around a desktop, or have multiple desktops and having to keep them in sync. When I need actual horsepower, I have a Xeon workstation at my house, and my work allows me to leverage it remotely if needed. Guess what? I basically only turn it on for games.
This is all getting rather stupid. Laptop aren't for serious work? What planet are you on? You like stationary devices because you like to compartmentalise your life. Well thats great for you, but it's hardly normal.