I installed the latest build and had a look at the new Calendar and Calculator... Microsoft is still trying a touch-first, one size fits all approach with Windows 10. It's actually going to be much harder to get away from all the Metro crap this time around that it was on Windows 8.
Non-touchscreen people will go a long way to getting comfortable with the new user/OS interface if they learnt how to use a touchpad, which W8.1 (and likely W10) is very user-friendly towards and I find it quite intuitive once you know the gestures to perform for common actions. If your PC doesn't have a touchpad you can buy USB ones
Tutorial: Precision touchpad - Windows Help
This is a random Dell wireless one I found that can be added if you don't have precision-touchpad fitted device:
Dell Wireless USB Touchpad
And they are not doing a good job with the modern UI. I use High definition themes and many parts of the modern UI are not integrated with the high def themes. The end result is that you cannot work with those pages and have to always switch back to a normal theme. That is completely unacceptable and a showstopper for me.
Picture 1 shows my high def as it should be. Picture 2 shows e.g. the update page in high def where some of the hig def appears but the background is white. And since the writing in high def is white and the hyperlinks are yellow, you cannot really read anything.
In my experience with Microsoft all the versions of windows have made it. In fact even thought it maybe dead some companies are still using windows xp and ive kept vista for 6 years. my first computer I ever actually had bought myself had lasted me about 10 years.