The stories of Hercules aren't a game.
Thank you for summing up in one sentence the problem I always seemed to have, but could never entirely put my finger on, with Box’s ideas about gaming.
He wants it all to be a story. Stories don’t typically categorize undead into dozens of different types with different names... so Box wants every undead smashed into one critter with a single name (ex. wights in GoT) because that is how it would work in a story. Stories also often feature unique monsters; there’s one Minotaur, one Medusa, etc.
Meanwhile, my gamer brain takes one look at those ideas and says “why would you want to add confusion and/or extra work for the GM by lumping a bunch of monsters under the same name and possibly just having a single stat block the GM has to adjust to match the level of the PCs.”
Stories also rarely make distinctions between more than a couple types of magic, so Box sees no point in having distinctions between a druid, cleric of a nature god and warlock with a nature patron.
Meanwhile I see all the ways the different classes could appeal to different play styles and allow different experiences in different campaigns.
Stories tend to have relatively flat skill growth (maybe a magic protagonist gets a better handle on their abilities in an origin story or learns a specific spell to deal with an episodic McGuffin) so Box doesn’t feel PCs need as much growth as a typical RPG presents.
I do somewhat agree in the sense that infinite vertical progression can lead to needless number inflation that slows things down (quick, what’s 6 + 7 + 38... that’s what a basic attack in 4E at high levels could look like), but that doesn’t mean PCs should remain static. My own sentiment is to cap vertical progression at some point before the numbers get too large, but then allow infinite lateral progression after that
Box seems mostly interested in RPGs as a system to create stories rather than as a system to create a good time among friends. My feeling on CR systems is that a good one can make it easier to get those good times by allowing the GM to easily judge the degree of difficulty they’re setting up (and old school HD with *s where each denoted abilities that made a monster tougher than HD alone indicated worked VERY well as a CR system). A bad CR system though can make it harder to get a handle on what will make a good encounter and so the system would be improved with no CR system at all.
Or the short version... good CR system > no CR system > bad CR system.