Nobody /needs/ a MacBook Pro. They're just fancy toys.
Spend half the money on an inexpensive brand and get the same laptop.
Linux will run on anything ( literally! ), so just buy the laptop that fits you the best, and don't worry too much about the rest.
Personally I've been developing on a modest 10' ASUS eee PC for years.
Ubuntu loaded with all of the above and much more have been no problem at all.
Lately I've been considering replacing it for the new 12' model though, since both the keyboard and the mousepad buttons are beginning to show wear from using it so much.
Macbook Pros are premium notebooks in the exact same way high end Thinkpads are. The price between a Macbook Pro and any other high end notebook is competitive.
With an inexpensive brand, you're getting inferior screens and flimsy plastic bodies. The specs might line up on paper, but that's as naive an approach to comparing hardware as you can get. Buying based on a flimsy spec checklist versus matching up the device to your real-world requirements is going to result in a great deal of buyer remorse.
If you're a road warrior, the last thing you want is a laptop with a flimsy body and weak solder points on the ports. If you are using your laptop as your only screen, you don't want to be spending >= 8h a day looking at a cheapass LCD.
Just like you don't see professional carpenters using dollar store tools, as a professional developer, you need to invest in quality hardware - regardless of the brand.
I'm quite serious. I am however also aware that I'm upsetting the entire Apple fanboy segment in here. (with slight intent admittedly)
MacBook Pros are premium indeed. But unless you're looking specifically for the "premium" look, then there's no reason to default to Macs.
Please bear in mind that I base all my comments on first hand, personal experience.
As stated I've been running on a tiny, flimsy, plastic thing for years.
My trusty machine have been thrown around and even landed on a stone floor from ~2m, with me onto. I have the marks to show for it, but the machine merely chipped at the edge.
Your argument about the LCDs being inferior I simply don't follow. What makes you think you're getting a different LCD in your MBP than everybody else does? It's the same technology as in all other machines out there.
I know specs are easy to dismiss, but honestly, it's not the extra shine that makes your computer run faster.
You hit the nail on the head (pun intended) with your analogy - why should the carpenter choose a specific brand or hammer just for the aluminum handle? Inexpensive is not the same as "cheapass".
You get plenty of quality machines at half the prices of a MBP.
Personally I've been developing on a modest 10' ASUS eee PC for years. Ubuntu loaded with all of the above and much more have been no problem at all. Lately I've been considering replacing it for the new 12' model though, since both the keyboard and the mousepad buttons are beginning to show wear from using it so much.