> Make it DVI or whatever you want then. I still need a video output for another monitor.

There is thunderbolt, DisplayPort, mini HDMI, and micro HDMI. Any small form factor laptop has at least one of these. DisplayPort, mini HDMI, and micro HDMI are all standard connectors. Mini HDMI and micro HDMI can be converted to DVI with connectors only and no additional active electronics.

> Still inconvenient at least. USB Ethernet dongles also have the possibility of not being able to be used for network booting.

If you're already carrying around an ethernet cable, just leave the NIC attached to the ethernet cable. You said it yourself that you have no issue carrying around 10 pounds worth of electronics, an ethernet dongle only weighs a few grams.

Note that many laptops simply do not support network booting, however these newer laptops (especially the macs) have proper networking built into the EFI firmware. Additionally, note that USB 3 and thunderbolt have pushed the bar for what you can do with external peripherals. If your only option for wired networking was a USB 2.0 networking adapter, then yes, I agree, that would be a joke. The USB 3 and thunderbolt NICs are actually quite good though. The USB 3 NIC that is sold by Apple supports every networking standard you would expect a built-in NIC to support and can achieve gigabit speeds without issue. It is additionally supported by the linux kernel out of the box. I actually find these NICs to be quite valuable when working in data centers as I can connect my laptop to multiple networks which have an air gap between each other by using multiple USB 3.0 NICs.

Samsung Series 9 ultrabooks don't actually use USB or Thunderbolt for the external NIC, instead they just use a connector that is thinner and provide an adapter to attach a normal ethernet cable to it. This allows them to have a normal onboard NIC and still maintain the thin form factor.

The thing that has reignited support for external peripherals is really USB 3.0 and Thunderbolt since they provide enough performance to support high bandwidth external devices.

Note that I'm not an Apple "fanboy" by any means, I use a work-issued Macbook Pro because it is relatively compact and sports a 500gb SSD, an 8-thread I7, 16GB of RAM, and exceptional battery life. I run linux on it and booted OS X fewer than 5 times so I don't actually benefit from Thunderbolt and as a linux guy I don't advocate proprietary connectors. It's really hard for me to say that Thunderbolt is inconvenient though when I see colleagues plug a single Thunderbolt cable into their laptop which is daisy chained to multiple 32-inch displays, gigabit ethernet, external hard drives, and multiple USB peripherals without any performance issues. As the industry continues to push the bar for high speed external buses, we'll continue to see the practicality of external peripherals increase.

Different form factors suit different purposes and different people. I own multiple laptops because of this, but I actually far prefer high performance desktops over laptops as I work on enterprise virtualization software and frequently need multiple hardware-accelerated NICs, a physical raid controller, 32-64GB of RAM, etc. No laptop meets these requirements so I go with the most portable form factor possible instead of using something in the middle which I find to be a mediocre compromise between portability and performance (adds more size and weight, but doesn't actually help me get more done). Most people have far lower requirements though and a macbook air will work just fine.

The important thing to remember is that no one is taking away the other options and all parts of the industry benefit directly or indirectly from the advancement of technologies which allow laptops to be made thinner, lighter, and less power hungry. Buy whatever suits your taste, it's great that we have options.