When 5e was in playtest, DNDNext used a high threshold to stay in. Since tis was before 5e even came out, this made anything the fans of older editions didn't like not reach the threshold to remain in the game skeleton. Some of the newer ideas and concepts where dropped completely, patch on later, or explored in later books to be patched on then. An if you look at most of the new ideas that made into 5e, most are wonkily unbalanced.
5e was never designed for new players. It was designed to pull in old players. That's why there was no stress for DM support. It was designed for people who already knew how to DM or would just run printed adventures straight up.
OneD&D is keeping that skeleton designed around grognards. It's why the Wildshape debate is happening (Copying 3e's bad wildshape and made it the core of the druid). It's why Aardlings aren't making it in (never explored other types of cosmology). It's why there will be very likely be chaos when the Warrior packet releases.
The circles aren't fitting into the squares. So the circle fans are not excited about what they see. And the square and rectangle fans already have their games.