Well the sudo approach is useful, but for a sysadmin or programmer who is installing packages and moving libraries around, it seems kind of limited to me. Granted, it does prevent the newbie from accidently chmod'ing /usr, or deleting root, etc. And you can use apt-get( or whatever ) for package management, but that limits your exposure to what is really going on in the system. I think programmers should build from sources, so they get a good idea of what programs, and libraries are really all about. Package Managers put an artificial layer of abstraction between you and the program. I also find it more secure, to specifically have to log on as root to do system stuff. Relying on sudo, you may fall into a false sense of security, and walk away from your machine thinking "I'm logged on as user so it's safe", but anyone can walk up to your console and run a sudo command.

Watching a system boot in console mode gives you an entirely different perspective on what goes on in /etc/init.d. Of course a user really dosn't care, and probably prefers not to know; but a programmer really needs to know what goes on underneath the gui surface.

As far as a "button hold at boot" ,booting Ubuntu into a console, I think that only boots to what is called single user mode(runlevel 1), and is only for system emergency maintenance. What is normally referred to as "booting in console mode", is multi-user mode, with network, (usually runlevel 3). Ubuntu does have a server-version which does this, and has no gui. They also have a special "alternate install disk" which is text mode, for finicky systems.

What I am trying to point out, is that Ubuntu, in the name of newbie safety, has made difficult, what is easy in most other distributions. If you wanted to study programming, you would be better off with a more straight forward distro.

I started with linux probably about 10 years ago, when gui's were just a novelty item. And until just a few years ago, every distro, would install into multi-user-console mode, and after that you were given the option to try and install X ( which was often very difficult because of the lack of drivers). Now, the opposite is happening. Everything is going directly to gui, and the internals are being hidden from you. Often, many servers and services are auto-installed, and bloat and slow down the system. Someone who understands the console mode, more easily understands what he needs and can customize his system for his own needs.

But all in all, I think Ubuntu is great for spreading linux, and maybe it would be better for a large group to know how to handle sudo, so they can answer sudo related questions as they come along. Me, I'm an old dog, and refuse to learn the new tricks. :-)