> It is astounding to me that someone would complain that a non-root user cannot install software.

Depends on what you mean by "install software".

If your definition is "put an executable in a directory that is in every other user's standard $PATH", then yes, this is an absurd complaint. Of course only root should be able to do this.

If your definition is "make an executable available to run as my user", then no, this is not absurd. You absolutely should not need root to be able to run software that doesn't require root privileges. If the software requires root, it's either doing something privileged, or it's doing it wrong.