First person shooting exists within the game. It has FPS elements in that it literally contains first person shooting... FPS, action, RPG are not mutually exclusive labels.
Also you can also pass off any design issue as player preference since there's no objective standard. If you were to carry around some the same sort of weapons IRL, your field of view would not match very well with the field of view you get when you're in first person and your character is carrying them in FO:NV. That's a fairly objective way to put it. It's most noticeable with pistols, most melee, and assault rifles I think - lever and bolt actions don't seem as bad. Melee it's like your char is intentionally holding the weapon right in front of his face - and it doesn't make much sense since it's not like it even aids in hip shooting the way seeing your gun does. Having a different view for crouching, standing, and moving might've helped too. It appears the standard view is set to a certain period of the 3rd person run animation in which the weapon is at it's closest to the character's head - and with one handed melee weapons at least that's a fairly extreme perspective to have 100% of the time in first person.
it's not a design flaw however you look at it, can't be because there is no "right" or "wrong" way to do it, some people will literally scream that it looks bad if you have the trigger hand showing while holding a rifle, some scream when you don't show the trigger hand, it can't be a design flaw because no matter how you do it the playerbase will always have conflicting opinions, it can't be done right or wrong, the only solution would be to have an option for it, but that isn't nearly as easy as it sounds.
so in this case the issue lies entirely with the players preference.