It's been a while since I used Gentoo, but most of the serious users consider build-from-source as a feature and don't penalize portage for that. I believe you

It's been a while since I used Gentoo, but most of the serious users consider build-from-source as a feature and don't penalize portage for that. I believe your parent is referring to the sometimes annoyingly long dependency computation time of something like emerge -uDN world.