"We know that cognitive load is reduced by minimizing visual clutter, which is often achieved by increasing the amount of spacing between controls. We also know that developers want as much space as possible for their coding environment. Balancing these two attributes against each other is a tricky proposition. To that end, we’re increasing the perception of space by using lighter weight control styling to reduce cognitive load. We’re also making minimal increases in target size to reduce the likelihood of accidentally activating the wrong control."
We are developers, not mobile casual users: I want the most tools in the smallest amount of space.
I don't wan't 500 pixels of damn padding between menu items.