Player feedback is always important.
There are many female characters because every mother needs a daughter, and every daughter needs a mother. In early story drafts, there were too many daughters whose mothers were professors at the college and had side jobs. Adding more mothers to separate those roles also meant more daughters. The characters who interest players the most will get more screen time outside the central story arc.
If we look at the game mechanics, there are essentially three. The Affinity and Persona systems are used to progress with characters, with difficulty used to raise or lower the levels needed. The phone allows the player to track that progression, and the computer is just a larger version of the phone.
Jobs are just another way for players to spend time with various characters. This is no different than agreeing to spend time with characters for other reasons, such as Kimberley's yoga class. Money was added because players simply didn't want to 'work' without a monetary reward, even though that wasn't the point. With money comes a need to spend it.
You can ignore all this and just focus on the girls. Like with modern FPS games, you don't need to gather resources, craft, or upgrade if that's not your play style.