"Intuitiveness" is AKA "resembling the current norm" when it comes to UX. Updating an aging UI to fit current patterns makes it more cohesive with the operating system, attracts more new users, and avoids confusing those new users.

Attempting to paint "strong usability" through the lens of existing users only (the guy who already knows how to use a rotary phone) is a lopsided view of the goals for an app creator.