There's no real point in designing for the last group but IMO a designer needs to account for (and design for) all of the other five. The part of your quote I bolded says how to do just this. And yet WotC only designs for the first three groups.
Which is why I keep calling for things like novice levels and incremental advances.
They are
very literally the tools you need to craft the kind of experience you want. Like those are literally THE rules needed for cultivating a diverse array of experiences. They equip the GM with multiple clear, explained levers they can pull for producing various things. Consider: The OSR GM desires a high-lethality, gritty survival experience where players are inherently at a disadvantage that they must overcome by cobbling together something from limited resources. This is empowered, not diminished, by giving the GM precise, fine-grained control over how many resources the players have: HP, defenses (saves/AC/resistances/etc.), training (e.g. weapon or armor proficiency, skills, etc.), supernatural powers (abilities, spells, psionics, what-have-you). When robust rules for this are provided, the OSR GM can clearly and, within statistical variance,
accurately understand both what power (or lack thereof) their players will possess, and the risk posed by various challenges to them.
But now consider the (very)
new-school GM, who desires a gentle, easy introduction. They want to avoid overwhelming players with too many systems at once. Their players are very liable to make mistakes, and having those mistakes be too punishing will drive players away from D&D entirely. They
also reap enormous benefits from having precise, fine-grained control over the players' abilities and resources, because that means they can furnish their players with characters that are relatively durable (so they can
survive a few small mistakes or one big mistake, or the like) but also relatively sparse (so they don't overwhelm the new player). Far from being a "serve A instead of B", the exact same system actually does meet the needs of
both people, despite their wildly divergent interests.
It goes even further though! Imagine the 3e-style GM, call it "middle school" (tongue
firmly in cheek). They want a game where everything really does grow naturally out of what was already known. Where the world proceeds like the deist "clockwork of the universe" conception, and mastery is found in those who don't just correctly understand the clockwork, but learn how to
predict it in advance. Where the world expands and iterates.
These people are ALSO helped! Because having this level of fine-grained control early on means that characters develop entirely "organically", and may end up in highly divergent trajectories from what was originally sought, simply because the choices that made sense were not the choices that ruthless optimization would have indicated.
All three of these GMs are served by having robust, well-built rules for characters that are "before" level 1. All three of them benefit from being able to parcel out character advancements so that levels aren't quite so chunky.
And for those who have no interest in those things? Their presence in no way harms their experience.
This is why I push
so damn hard on this issue. It is one of the
only places in all of D&D design, as far as I can tell, where there really is a pathway that helps damn near everyone, and the few it doesn't help aren't affected either way. The only people that this raises costs on is the designers, who have to put in the effort to build such a system.
I think you know why I find that a completely acceptable cost.
