Totally agree with your sentiments. Classic Microsoft for every 2 steps forward there's always a step back.
The major complaint about Win 8 has always been about the lack of a start screen and its unintuitive UI when using a M+KB.
Win 8 with touch however was GREAT the way it was! All msoft had to do was reintroduce the desktop start menu the way they have now without screwing with tablet mode!
I know it's just a preview but I'm 99% certain they aren't gonna do a 180 and change vertical scrolling back to horizontal in the modern start menu. Taskbar in tablet mode is just downright ugly (tho I'm sure that'll change), tapping on the small "All Programs" font is annoying and nowhere near as smooth as swiping up. Swiping from the edges for charms and last used apps used be soo convenient for 1 handed operation.. both features now nowhere to be found. The desktop start now takes up a large portion to the left of the modern start screen even in tablet mode, scrolling through all apps is now a pain with all desktop and modern apps mixed together in one long vertical list.
I've always been a die hard msoft ****** but damn they are sooo out of touch now. Same for Windows Phone 10 with its weird new Androidy/Metro design language. If major changes aren't made...which are unlikely seeing how win 10 launches in mere months... win 10 is going to be to tablets what Win 8 was to desktops.
On a more positive note... Win 10 is now great on desktops