An "ordinary user" is incapable of installing an operating system. They don't even know what an operating system is.
A linux distro should assume that if the user is installing the OS himself, he isn't ordinary and should quite simply ASK what the user wants to install, instead of assuming. This sort of stupidity forces me to look for the most minimal install ISO for every distro I deal with.
"""An "ordinary user" is incapable of installing an operating system. They don't even know what an operating system is."""
No, that's a "strawman user", or some grandma.
There are tons of ordinary users that can install Windows. And almost all Mac users can install OS X (there's not much to it).
They are no programmers, they are no superusers, they are no admins. They just know how to insert a DVD, answer a few questions and press next.
There's no reason to not be able to do the same with Linux, or for a linux distro to assume "that if the user is installing the OS himself, he isn't ordinary".
Doubly so for Ubuntu, who wants to be the people's friendly distro and change all that "Linux is for geeks" mentality.
For distros targetting ordinary users the office suite should come preinstalled as long as you can't buy one at Staples.
That said this is also part of what makes Linux shine compared to especially Windows: Usually everything is installed and Just Works in 20 minutes after started installation. (Have been fixing peoples borked Windowses from '95 to '08 so I'm allowed to be opinionated here. : )
That's mostly not true, nearly every windows install from a store bought machine has trial versions of office already installed. Word and Excel are expected programs for most people.