Quite often, less really is more. One staple of computing in general is the perceived need for options. Painting yourself into a corner a lack of options with hardware or software is never a good thing, but there's a difference between that and trying to paint the room with a half-ton paintbrush.
It's no secret that Steve Jobs -- and by extension, Apple -- is very interested in pushing the design envelope. Going back a long way, except perhaps the dark years in the nineties, Apple has had a history of making big changes and taking big chances with their hardware. The Mac was really the first home computer to have integrated SCSI and a mouse. Apple computers were among the first to be produced without internal floppy drives. The Apple Newton was one of the first usable PDAs and even today enjoys a startling number of users. NeXT Computer, founded by Steve Jobs in 1985, is looked on as being way too far ahead of its' time, producing a line of UNIX-based workstations running the NextSTEP OS, an OS that is the precursor to Apple's OS X. Apple's OS X itself is a complete and total departure from Mac OS -- a move that helped reinvent Apple. The iPod, of course, was instrumental in building a whole new industry. There are more examples, some flops, some not, but they have a common theme: out with the old, in with the new, whether you're ready for it or not.
Apple's design theory seems to be "Rounded rectangles, white or silver, as few seams and ports as possible, as few cables as possible". If Apple designed a Swiss Army knife, it would look like an egg. Their products certainly are attractive, with clean lines and an overall minimalist approach. To get those clean lines, however, all those bulky ports and slots have to go. Quite honestly, I think Steve Jobs harbors a deep, personal resentment towards D-Sub connectors. That's the concept behind the MacBook Air.
In an age when you can still get a laptop with a parallel port, Apple has created a laptop with no legacy ports, even deleting FireWire from the specs. There's also no built-in optical drive. Many reacted to this with disdain, decrying the lack of an internal optical drive, fixed RAM, and limited ports as being too limited and artificially handicapping the system. I've come to realize that I don't think that's the case at all. When I thought about it, I don't really need any of those things on a daily basis, and when I do, it's rare. Perhaps desktops need lots of ports, but not laptops -- not any more. In a time when I can buy a 16GB USB2 flash drive for under $80, why would I bother to carry DVDs and CDs? If I don't use those, why do I need the drive? If I need to transfer files between systems, I can use wired or wireless Ethernet, or that USB flash drive.
I get the vast majority of my computer-based entertainment via the Internet. Music and movies, and other forms of entertainment are easy to download from iTunes, Amazon, or anywhere. Though there are subscription services like NetFlix that are PC-only, that will likely change sooner rather than later. Occasionally, I'll buy a DVD, or a CD at a vintage store, and encoding those to MP3 and MP4 is trivial using a desktop system. I then get the benefit of being able to play them anywhere, instantly. I simply get more bang for my buck with digital files, and there's no reason I'll ever go back to physical media.
I also get the vast majority of my applications from the Internet. I can't ever recall loading a CD or DVD into a Mac to install software other than an OS installation. Even when devices come with driver disks on CD, I generally download them from the manufacturer's website since the version will be newer and hopefully better. The first disc I've put into my MacBook Pro in probably six months was the Apple disc that contained the MacBook Air's CD/DVD sharing installer. I won't miss it on the Air. With Bluetooth, I won't really need more than one USB port either. If I do, there are 3" x 1" four-port USB hubs on the market for less than $15.