I agree with you in theory.
The problem is the larger community. If you enter Wizard's forums you'll find that daring to not allow something from 4th edition leads to a large amount of attacks, and people posting about how they PM'd the community manager a list of people that should be banned for being "Bad community members". All of this after all of the 4th edition fans spent years telling everyone that if they didn't like a 4th edition feature they could just ignore it in 5th edition.
It leaves me with a choice, support 4th edition in 5th edition and spend years taking abuse for daring to exclude a 4th edition feature in my games, or oppose 4th edition in 5th edition and eventually that group will no longer be around to toss out abuse. It's a no brainer.
So basically, where I'm going with this is: This won't work until forums start shutting down those who feel not using something from 4th edition is cause to attack. I really don't think there's anyone who cares if WOTC releases a book designed to approximate 4th edition with 5th, I think all of the friction starts with the insistence that we use it or we're horrible people who should never be allowed to play D&D. Which is pretty much what the official Dungeons and Dragons forums consist of today.