[rakoo]

The two are not exclusive; in fact, "convention" means that out of all the possibilities a certain set is chosen and used by default. It is not possible to have a "convention" if there is no "configuration", otherwise it's just a limited set of features.

What the author says is that's it's good to have configuration, because then everyone can find what they want, but configuration alone is not enough. You need good defaults, and because "good" is subjective it means you need defaults that will please a specific category of users, and you need to go all-in on it because then your software will have its own identity. It also means that those who want to use the software another way can still do it because it's configurable.