rPi claimed to be .
We know how difficult it is for techies to discipline themselves and not, /get-carried-away. That's why you write the spec before you starting to code; you make a flight-plan before you take off.
Re. educational projects, rPi can learn from OneLaptopPerChild. OLPC also had yuppies in California trying to direct OLPC advocates in Nepal [with no main supply] via "your latest http".
It's like sitting in your office in NY and internetting to the bloke who is snorkelling under the water, that he should "Pour yourself a cup of coffee". He can't do that in his constrained environment.
USB is rather complex; but the details are well hidden, and standardised to the extent that it's in the BIOS.
Ethernet is quite complex, but it's not standardised and hidden in the BIOS. Something about different chips? IMO it's a mess.
A fundamental requirement of a rPi type project is the ability to install new/different stuff. It should NOT need ethernet to fetch/install packages. With the existing rPi hardware, a 3G USBdongle could get on line if the utility `eject` was supplied, by default.
~# ls -l `which eject` ==
-rwxr-xr-x 1 root root 20600 2007-02-16 21:54 /usr/bin/eject*