This reminds me of the debate that was happening in the
Warcraft communities in the late 2000s, during
Rise of the Lich King. A vocal minority were loudly crying out that the game had gotten too easy and needed to go back to being more challenging. And the designers listened and cranked the difficulty up for
Cataclysm, helping to trigger a precipitous decline in the game's popularity.
One difference here is that although the rules have become more forgiving, the difficulty of 5e is really up to the DM. Want proof that it is not a problem to create a devastatingly difficult game out of it?:
Battles have gone badly before in Dimension 20, but not like this
The other is that you can still easily access those earlier versions of D&D any time you like. A lot of these criticisms about the game being too easy, not focused on the dungeon enough, etc. are coming from folks who aren't even playing 5e. Which is massively more popular than any previous version of the game. So why would WotC want to change the game to suit the tastes of a small sub-set of players who probably aren't going to buy it anyway?