I guess my question is; why do classes have to be a zero sum game? Why does me being really good at X mean that I must completely suck at Y? Why can't I be really good at X and passable at Y?
my guess is they are building the game right now so you are at least passable in Y. But someone with different taste could ask the opposite, why do i have to be good at everything?
i have my own preferences there, but ultimately the designers of D&D need to serve the majority of players, and that decision will be based on what they believe the majority wants, not on arguments overfans make to support their balance preferences.
I have done a bit of this in my own games. We don't have a class system,but have a skill based game where skills are divided into six groups. We decided to silo the point spread across groups originally, so you got 12 points in two major groups and 9 points in two minor groups. This skill groups basically cover different areas of play (combat, social interation, physical athleticism, professional skill, knowledge and defnses).
the feedback I got over time was the 12-9 difference was too narrow. Essentially, players were asking me "why can't I suck at a given category". So we changed it in two steps, first we introduced a rule to burg skill points in one category for points in another (get rid of all your combat points for three in physical). That helped but we still heard from people who felt they were too strong in their secondary skill groups. So we adjusted the secondaries to 6 points (and there was even talk of going to 33). That seemed to work much better for people. So now you have 12 points in stuff you are good at and 6 in things you are not so good at. But I coul easily drop that six to a three if feedback is such that folks seem to prefer it lower (and at three points then you have a number approaching 10% goodness).
I am sharing this to say I don't object out of hand to making characters good in areas outside their specialty. I think the question is how high or low that ought to be. And that is going to be based on what peple want. But i dont think there are any wrong preferences here. For every four people wh. Like our six to twelve point allocation, i will meet one or two people who want 12-0, 12-3 or a sinlge pool of points to spread over all their skills. Each of these match different preferences, but they also facilitate different styles of play.
Now my own personal preference is for something closer to 12-3. But i haven't found that popular enough among players to incorporate. I don't think 12-3 would be objectively bad design, because it supports a style of play and there are people who like it, myself included. But it wouldn't be the right design decision or this gameline. My attitude is somewhat similar in D&D. I might want something like 90-40-10 in the three pillars. But more fans might want 80-50-20 or something. Whatever the bulk of the players seem to want, in my opinion that is what they should do. And if tgey feel like it, they can include optional rules for scaling that down for poeple like me and scaling it up for people like you.