The goal isn't to enable players to ignore light.Like you said, you could run an all-Darkvision parties with dwarves (or drow, etc.). Now you can do so with a more interesting (not monolithic) party selection.
The way you had to create a less interesting party was the main thing that kept parties to using light. Like I said, the change might seem innocent enough, but it ends up messing with the game's expectations.
The game is clearly meant to be run for a party using light. The feeling of dread fundamental to human nature when you're in an "island" of light, surrounded by darkness, is one of the simplest and most effective tools in any DMs toolbox.
In this case WotC comes across as clumsily tinkering.