Variety, tradition, and a lazier hit confirm, I'd wager. Her f+a command normal seems much better, and more "useful" here than in most other games, so she already had 2 slower hits to use before combos.
Maybe it can also be used as a sorta setup for Splash, as well?
On Block and vs Guard Point, it also might leave a little less gap than the c / d -> f+a too, making her pressure just slightly better?