Perhaps I'm being a little hard on the Linux users. Many of those at Linux conferences are carrying MacBooks.
I was this guy for a while. I like open source, but it's not my top priority. I just want a computer that lets me get done what I need to get done most effectively. For admining *nix boxes and diagnosing networks it's pretty helpful to be on a *nix box yourself, but which variety is not really important as they all tend to have the same basic tools available.
A Mac laptop provides a *nix machine that is 100% supported by the manufacturer with a well-known OS and a good selection of both free and commercial applications. For a while they were better built than most too, my last Macbook Pro was the generation before the "unibody" models and only Thinkpads really compared as far as sturdiness. I haven't yet found a laptop that feels stiffer than one of the unibody models, though some of the PC vendors have adopted that design as well and are thus in the same range.
These days I'm running a refurb Acer because the battery on the MBP wore out and I couldn't see putting more than a third of its remaining value in to a replacement on a Core 2 where the motherboard couldn't reliably handle 4GB RAM sticks (only 2+2 was officially supported, though 2+4 was reported to work with most sticks, 4+4 was not usable in most cases). Core i7, 8GB, 1080p, and 100% of the hardware works in Ubuntu 14.04 so it fits what I need in a laptop.
Why anyone who doesn't need Final Cut would ever buy a Mac desktop I'm not really sure. The G5-like Mac Pro was intermittently price competitive with other workstations in dual-socket form but the new trash can model strikes me as the second coming of the G4 Cube.