Couldn't disagree more. The Tools team has made huge progress - the new emulator is so much better than the old one, ConstraintLayout is a huge upgrade for using the layout editor, and there's a huge push to fix performance with the Gradle plugin.
I'm seeing pushes to do this, and promises of that, but this is all stuff that should have been there from the beginning. The Preview window still stumbles on views imported from the Support Library, the emulator is a little better but still not great, Instant Run is a disaster, and Constraint Layout just now came out of beta.