Female characters tend to be written with the view that they are "female" first (i.e. a stereotype of what a woman is, does and likes) and characters second. Therefore if they aren't the main character or there's not time to flesh them out much, they tend to default to that stereotype. Hammie is a woman, therefore she exhibits "girl" behaviour ("cute", emotionally supportive), likes "girl" things (idol singers) and aspires to a "girl" ambition (being a teacher.) The show is not interested in taking her much further so that's what she's going to boil down to.
Female had nothing to do with my statement. I said that more because her wanting to become a teacher came out of nowhere. You don't have to keep bringing up non existent sexism every time it seems implied.
Everyone else's goal fit what the basis of their character.
Lucky is going back to his original plan of seeing the edge of the universe.
Shou wants to be higher up in the resistance, which fits with his current ranking.
It was simple but Spada wants to be the greatest chef.
Raptor wants a romance, which fit with some of her funniest moments this season.
Champ's going back to wrestling, which seems to make him happiest, especially regaining his title.
Stinger's only known fighting, which could fit his loner style.
Balance is going back to treasure hunting.
Naga wants his home to see emotions aren't a bad thing.
Garu's is also simple, but he's loyal to Lucky so why not follow him.
Kotaro wants to be like the hero they found on Earth, Tsurugi, and plans to have the same title.
Hammie wants to be a teacher, so she can help kids. But she barely had any interaction with kids, in fact even Kotaro didn't like her at first.
Plus Raptor has been an okay character. Yeah she's been sidelined but her position has actually fit that. She did what she could for the Orion and her dreams matched up with romantic side. Truth be told, the ones who got sidelined the most were the ones who could make the Orion ship work. Balance and Naga helped with maintenance a lot in the starting episodes. Shou as Commander sticks with Raptor in order to still give mission specs among other things.
I just felt the after goal was a bit out of nowhere for Hammie's character. If Garu said, "I'm gonna lead my tribe back home in honor of my brother" I would've been like, what?!