Would people who use laptops agree with this?
I do have a laptop, as I have occasionaly need for a portable machine. Given the choice, as right now for example, the laptop is switched off and I'm using the desktop.
The first problem with laptops is inadequacy of the various pointing devices. My current laptop has several, but they're all crap, so I carry a mouse around with me. No big deal that, doesn't take up much more room in by briefcase. If I'm asked to use a laptop that doesn't have a real mouse I find myself trying to remember how to drive Windows from the keyboard. (Of course this won't worry you if you use Linux, as that's all keyboard driven anyway.)
The next problem is that you get a crappy little screen, unless you want to spend
lots of money on your laptop. Still, if you only want it for emails and web browsing I guess that might be tolerable, but that doesn't suit me for software development. You could just plug in a proper monitor, but you're not going to carry that around with you so what you end up with this way is just a small slow expensive desktop.
The next problem is that you get a crappy little keyboard on which I find typing impractical. If you're a hunt-and-peck two-finger merchant that may not bother you, but as a properly trained touch typist it does bother me. One solution is to carry a proper keyboard around with me, but actually I don't bother - instead I don't do any serious typing on the laptop, if I've got some typing to do I use a desktop.
Finally, for the same price a laptop is small and slow compared to a desktop. Again if you only want it for email and web browsing that may not be a big deal, but there's really nothing at all you can do about how slow laptop disks are if you need to do any disk intensive work.
I used to use my laptop largely as a portable hard disk, to move stuff from one desktop to another when it was a bit big to email. These days USB memory sticks meet that requirement so I use the laptop less and less. Just email whilst travelling mostly.