No one would want to work on them. I also think that a laptop larger than 12” is a waste, due to weight and bulk concerns. I have a 12” and it’s large enough to do some work on, but small enough to be portable. a 14”, 15” or 17” laptop is the opposite of portable. Besides a desktop will always be better and more powerful than a laptop.
The best laptop I ever owned was an original Apple 17-inch aluminum PowerBook. I had it almost six years (swapped out the hard drive after three years). The machine was a rock. Literally and figuratively. It just worked. The 17-inch screen was wonderful. I seldom turned it off, even when traveling abroad. Close the lid, slide it into the bag, take off. I never had a Mac perform better or longer.
I’ll never buy another one.
The screen real estate is nice, especially when compared to a netbook or even the new MacBook models, but I found it difficult to do serious work on even a 17-inch screen after having a 23-inch Cinema Display on my desktop. In the future, I’ll probably go for a MacBook (small and portable) but hook it up to a larger display.