Yeah, as it is we never see her interact with any of these small people she's invested in. All we see her do is pranks around Skyhold or the Winter Palace, which is more about making the top look bad than improving things for the lower classes.
Because we don't actually see her interact with her people, it makes her seem like she's more into the idea of the little people than the actual people. She's a Jenny because it lets her beat up nobles, not because she cares about nameless peasants. I'm not saying that's necessarily true, just how it comes across to me in the game.
I agree so much.
That's a huge part of what bothers me about Sera.
I'll admit I used to be one of those people who saw her as just painting nobles as convenient targets of her criminal activity with moral impunity, but now that you've mentioned it, this could just be an issue with "show verses tell."
Even the in-game character descriptions acknowledge her as "a selfish criminal." In-game, she often mentions things like, "Fixing the world ought to earn more sovereigns than this. We need things back to normal so I can go play" and "I just want things back into neat little categories" and "Helps me, helps people, helps you, in that order." The game makes it clear that while she does care about "the little people," she's also out to make money and have fun for herself. She enjoys pranking, robbing, and even killing nobles (she does love to "stick people with little arrows"), so given how much we see of that and how little we see of her interacting with the "little people" she claims to care about, it can make it easy to interpret her as someone who just labels all nobles "bad people who victimize little people" so as to give herself moral license to vandalism, rob and kill with impunity. And the Inquisitor can even accuse her as such in-game!
If we'd been shown more instances of her interacting with and helping the "little people" she claims to care about all game, there would probably be fewer instances of people (myself included) accusing her of just using the little people as an excuse to rob/kill nobles with moral impunity.
Also, I get the impression that she was written to be polarizing and that she was intended for a lot of people to dislike her, hence why she is the only companion with the dismiss dialogue option present in her main dialogue wheel for the entire game. I don't like that her character's intention is to want people to kick her out. Unlike, say, Vivienne, whom people easily dislike but will never leave once recruited.
I dunno... I remember the pre-release hype, and in nearly every interview with the devs about the game, whenever they were asked, "Who's your favorite Inquisition character?" or "Who do you think is the funniest character?" or "Which companion do you think players will love most?" they almost always said, "Sera!" (and/or occasionally "Iron Bull.") I got the very strong impression at the time that the devs expected most players to love Sera, and I was expecting to love her too based on how much the devs all seemed to adore her.
Imagine my shock and disappointment when not only did she not appeal to me (sorry Sera fans, I find her too childish, hypocritical, judgmental, mean-spirited, and closed-minded), but she wound up being one of the most divisive companions in the fanbase (right beside Vivienne, whom pretty much everyone guessed would be their most hated/beloved based on her demeanor and Circle stance).
Now that you've mentioned it though, it is kind of telling that you can dismiss her at any point all game, so... *shrug* Maybe there's just something I missed. Maybe she was meant to be polarizing after all. Who can say?