You do not need root access to use modules or install them. It is just a little more painful to install.

The question is more why List::MoreUtils has to exist at all. Why not put the functions in List::Util and do away with List::MoreUtils completely? Isn't it simpler and cleaner to have one utility module instead of several?

One reason is I use List::MoreUtils for years and do not plan to change all scripts. But a bit overdone, you ask to fold CPAN into the core? A lot of my scripts use XML::LibXML and DBI and HTML::Template. I like to get them into the core too.

Do you think it's cleaner to have all the oneliners copied and pasted into the start of every script that uses them? Do you think it's simpler to have to remember which of several list utility libraries each basic function is in?

Often yes, since I have to read learn every silly simple function. Sure it is not a problem, if I add some simple handy functions to my script as well. I even like the split between the core functions and the handy glue. Or you could use List::AllUtils, but thats again not in the core.