I agree essentials bombed. But the focus was applied in the wrong spot. A lot of the criticisms behind 4E were based on mechanical bias. They would have been better off smoothing out some of the rough edges and adding more options to the game, like allowing casters more spells, or martial characters more attacks. Or add more options for story pacing and healing.
I'm not familiar enough with 4e to comment.
But worse of all, you had a feeling that the developers did not want to stand behind their product.
I don't think that's fair. I'm sure they genuinely wanted to produce the best product they could, they genuinely put in their best efforts, and it just didn't work out.
But on the other hand 5E threw away most of the strengths and rules consistencies of 4E from the perspective of transparent and easy to understand rules (no DM gets to decide mumbo jumbo), and also dumbing down martial characters and enhancing spell casting classes.
Actually, I think this goes back to your first point: with 4e they tried to formalise an awful lot of the game, what with all those grid movements, the rolling revisions as they endlessly tweaked the game, and the corrections for those criticisms of mechanical bias.
And at the end of all that work, after years of tweaking and lots of complaints about there being too much errata, they ended up with a game that
still wasn't perfect, that
still suffered lots of complaints of mechanical bias, feat taxes, and the like.
At which point I suspect they concluded that the notion of perfecting the mechanics is a chimera - the more they fix some things the more others will pop out of alignment. Because any sufficiently complex piece of software always has infinite bugs. Much better, then, to simply skip all that effort - to note that the game will always need a human DM to fix some issues, so why not just built that in from the outset?
Either that, or Mearls just has a preference (either in general, or just now) for a more rules-light version of the game.
