As a 'kid' I'll try to give my explanation of why an increased cap appeals to me.
The main reason is striving to get to the next level (mainly the perk levels) and after you reach the top no more strife nor achievement or any additional perks. I feel the same way when I get the strongest weapon for my particular character build, as I've got the best now what?
This is all after having completed the game so the different story endings and pathways no longer feel like the rewards they were compared to the first time of defending the dam or anything etc.
That's my personal reasons, I do understand about balance, but this is something the developers should address (or if you have PC mod) if I didn't have the 360 version I'd have modded all the gripes I had away.
I understand your perspective, therefore I conclude there is a difference in view of FO games from say the average RPG/Role-player and say the average player who enjoys Grinding -pardon the loose comparison - thus arriving at the point of complete opposites to this argument.
In lieu of what you have said, I am actually the opposite: a lot of people view SR or AMR as the
best simply because it is high-end access but I think FO3 and F:NV bring an array at each top-end: Unarmed/Melee/ERG/Guns/Explosives but I must concede that weapons have taken a back-track to my focus in F:NV due to the major efficiency of most guns in normal combat experiences.
I foresee that in playing both F:NV and FO3 you will be one of the people who did not like the stop-track ending, since you say you do not feel any encouragement to replay the game differently, and this I think correlates to your liking of levelling/ranking/building up your character. Again, it is my understanding that the game is attempting to remove itself from the levelling principle as a major factor of its gameplay mechanics.
Reno