Dash 2.0: Provide simple, consistent user experience for the most common user
The Dash 1.0 was a simple, consistent user interface: You point at the thing you want to do, you click, you do it. The interfaces were at a consistent size and comfortable distance from the user.
Dash 2.0 looks very cool, but feels like a bunch of experimental interface ideas were mashed together in order to provide a bunch of features most users aren't going to care about, and as a result feels like an inconsistent mess. The interface is too close and results in eye strain, the different interface components are accessed using different interface conventions and the bar is easily accidentally triggered, and none of them use the simple grab/point interface conventions that have already been established.
Have you seen what normal users to do a pre-ribbon Microsoft Office app? After a few months, toolbars are all over the place, there's weird empty spaces everywhere, and they don't even know what happen to the bold button. This is what's going to happen after people accidentally start dragging their windows around when they just wanted to scroll something. If I'm clicking (sorry, waving my hands over) the library button and can't see my library because it's hidden behind the home window, your interface has failed. I can figure out what's going wrong, but the point is: I shouldn't have to.
Right now, Dash 2.0 feels optimized for the 5% of users that really care about spending the time putting the settings window in the perfect position in the upper left corner and have the opportunity to have browser windows running in eye-strain blurry resolutions, and it feels like those of us that just want simple experience to use the dash to quickly launch and manage apps are going to have a compromised experience.

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Alejandro Fernández Rojas commented
Also you forgot to mention that Core 2.0 is eating so much resources that makes users lower settings in games to run them smoothly (even on a i7/16GB/GTX1070 machine)