I gotta say, 4E is the first edition I felt like I could competently DM. It was just brilliant for that purpose. And it did, indeed, have a lot of hand-holding. Loved the advice in the DMG. The problem, I think, is that getting that info into a prospective DM's hands required a $90 buy-in as opposed to $30 for a player. Gotta fix that somehow.
I have played with the same group since about 1998. One of the other members have tried to DM a couple of times earlier, but it was basically unsuccessful. That is, until he tried running 4e. The big changer was how much easier it was to run planned encounters and have a fun fight. In earlier editions it was a fudge fest from him as he couldn't manage to plan an encounter that didn't go off the scale - in one direction or the other.
5e does seem to have the same type of predictability and also does seem to "fix" the slow (untweaked) combat of 4e.
I think Pathfinder has done so well due to the best adventure support ever. The only reason I didn't jump on it was that I was sooooo tired of the save-or-die mechanic and the slightly haywire math of 3e.
If 5e can take the predictable math from 4e, fast combat of [unknown system here] and good adventure support of Pathfinder I think we have a winner. Looking at how much adventure support 5e has gotten, I think we have a winner.