it being "more than enough" for some used to the FFXI system doesn't mean it's optimal, or confortable for everyone

As you said setting a ton of macro is an inconvenient waste of time, while putting an ability in the action bar takes a second. Switching between bars is also inconvenient and cumbersome.

Extensible action bars are pretty much a standard nowadays, and it would help a lot in making the game more more slender and streamlined.