Many heroes in literature use smaller or less efficient weapons like quarterstaffs or daggers. The argument seems to be that character concepts are 'peanalised' due to inflicting a few points less damage due to more limited weapon choices without balancing the limitations against other benefits.
Like who? Anyone who uses a Dagger is an assassin, and doesn't deal with HP. Some character's in literature are bare-handed, but strong enough to rip men in half.
Now, in DnD... yeah, there is basically no reason to seriously use a smaller weapon. The only possible advantage a dagger has over a shortsword is that it can be thrown (depriving you of a weapon) or hidden more easily. Both of which are very niche and rare to encounter. You simply aren't going to use a Quarterstaff over most martial weapons, because the staff is a worse pick with nothing to recommend it mechanically. But none of that is a character flaw.
I think the logic behind it is more that, when implementing classical interpretations of halflings for example, it's silly for a 3ft halfling with half the body mass of a half orc to have Str20, while at the same time, acknowledging that, in a different fantasy setting, people may want to do that. So, rather than banning outright, like 1e where Tolkien heavily influenced concepts and halfling Str was capped at 17, they allow it but acknowledge that it goes against the grain of the classical interpretation by making it fractionally less efficient. This is a compromise.
Yes, a classical interpretation of a halfling is that they are weaker than orcs. But being "weak" wasn't the character flaws highlighted in that story. And if you want a "weak" character, you can choose to do so. But some people don't want to play the classical interpretation, and calling that out as somehow not wanting character flaws is ridiculous.
There is also the issue that 35 or 30 DPR only matters if the monster has more than 30hp, so some of the penalty is only on paper.
Sure, if a monster has 30 hp it doesn't matter. But if you lose nothing by getting 35 DPR, why settle for 30?
Dex-based characters are more likely to be knocked prone and often feel more vulnerable in our campaign. The strength based characters are more resilient. There are definitely pros and cons.
What do you mean by "more resilient"? Harder to hurt? That's con and I've played plenty of characters with low strength but high con. And, how often are you knocking people prone? Knocking someone prone doesn't deal damage, so it can often be a far less threatening action from an enemy.
Yes, you can say there are pros and cons. But if you start including penalties that are only suffered by strength based characters... you are just increasing the cons without adding any pros.
Mobility and novas seems to be the biggest dividing issues for our characters but we do have players experimenting with all sorts of less efficient weapons, so maybe this is why complaining that a halfling can't use a longbow as a deal-breaker is such a head scratcher to me.
I've been playing the game for 40 years so I've seen the drift as new fantasy genres become mainstream and the game was tweaked to incorporate those genres and the differences between races / heritage have narrowed again and again, and become more modular. I do worry that any flavour is being removed in favour of mechanics as if characters are code in the matrix rather than variations on classical themes.
That said, if they had the core rules and then said and here are optional chassis that you can apply for certain types of campaign, I am perfectly fine with that.
It isn't a deal breaker because we can't possibly accept it. It is confusion over why it matter so much that we need to start penalizing people for it. The strongest Dex-based fighter in the 2014 game is a Handcrossbow Wielding Crossbow Expert with Sharpshooter. It does so so so much more damage than any other ranged weapon build in the game. So... why in the world would I want to turn to a halfling who wants to use Longbows or Heavy Crossbows, and insist they can't, and that they must use small weapons... like the greatest cheese combo they can find?
And if they can't use melee weapons... why not stick with range? If they can't be a barbarian, why not go warlock and get a Hexblade PAM lock that outdamages the Barbarian they were going to be anyways?
It is a restriction of flavor, with nothing to it but preventing people from diversifying concepts.