To be frank, whether or not you can have a decent halfling hurler barbarian is beside the point. I proposed a traditional axe-wielding barbarian halfling as an example. I could have said dwarf sorcerer or gnome magus or tiefling summoner. I was trying to demonstrate that a player could have some character concept that he or she thought was really cool but wouldn't be able to play it effectively because of the ruleset. Whether or not a different character concept is functional isn't the point. The point is that the original cool character concept didn't work because of the ruleset.
And my larger point is this: Aren't we savvy enough and mature enough and confident enough as gamers to have conversations about character concepts just between player and GM, without the hard-coded rules of the system getting in the way? I mean, we're here, having a discussion on a forum dedicated to RPGs. Obviously we know what we want in a game, right?
So let's posit two scenarios. If a system supports halfling barbarians, but the GM doesn't want them, a conversation could go like this:
Player: Hey, Bob ... I was wondering if I could play a halfling barbarian in this campaign?
GM: Well, I'd rather you didn't. It doesn't really fit with this Tolkeinesque world I'm thinking about.
Player: Okay, well I guess I'll hang on to that idea for some other campaign. How about an elf ranger with a longbow?
GM: Now we're talking.
But now imagine that the GM thinks it's a cool idea but the system doesn't support them...
Player: Hey, Bob ... I was wondering if I could play a halfling barbarian in this campaign?
GM: That would be awesome! Except ... let me see ... size penalty ... slow movement ... strength penalty ... Hmmm, your character's going to be kind of ineffective.
Player: Okay, well I guess I'll hang on to that idea for some other campaign.
GM: It's the system actually. A halfling barbarian is just never really going to work that well.
Player: <sigh> I suppose could make him a hurler halfling. That's sort of like what I wanted. Kind of.
GM: Maybe a dwarf barbarian? They're ... y'know ... pretty decent.
Player: Yeah ... that sounds ... good. I guess.
In other words, I think it's fine if someone doesn't want axe-wielding halfling barbarians or [insert some character concept] in their game, but why can't I have them in mine?