Obviously, Apple isn't building this to your specs, so they also don't expect your demographic to purchase them.
Myself, I will greatly enjoy the HiDpi screen and thinner form factor, and for the lack of ethernet, I suspect I'll survive fine with the dongle and WiFi.
I agree with you. First I thought, man I need Ethernet, but now realized since I have the thunderbolt display I have never used the Ethernet port on the laptop. If I need gigabit Ethernet, I'm probably doing something intensive so need the power cable as well.
I'm wondering if they are going to introduce 802.11ac as well. Gigabit wireless, Ethernet won't really be needed.