The way to make Windows 10 stand on it's own is to make the Start Menu truly powerful and beautiful. Custom tile packs (as in Android), jump lists, MS Phone "fly-away" style animations when clicking an icon, automated icon grouping options, etc... . The problem with the Start Menu now is there is simply no "gee whiz" or "wow" to it, unless of course you consider the Metro-style animated tiles rolling over an amazing and super useful feature.
They really need to release their design
Kraken and make W10 amazing to look at.
I think we're talking about more than just the start menu although that's also important. Their design language in Metro was good for touch.
1) The new hamburger menu is not as useful as the old one
2) The charms menu was good for touch but so far, that's no real replacement for it in Windows 10. Sharing, printing, taking a screenshot using touch etc have become more difficult on Windows 10. They were very consistent in Windows 8.1. Maybe they can include all the functionality of the charms bar in the new notifications center (as they've done with devices) but till that's done.
3) Searching in apps is no longer consistent as it was in Windows 8.1. This doesn't only affect touch users. Now each app has to have its own search button Vs using the charms search
4) Left right scrolling on the start screen is much better for touch (as can be seen in every other touch device) but that has been neglected to accommodate the start menu. I still think they can use both and I explained how to in my feedback but oh well)
5) Modern Apps had ease of use for touch (like the mail example I gave earlier) and the ease of use has fallen dramatically in the new preview apps IMO. Another example is with the new music apps. Previously, you could swipe from left to right on a song to select it and do it for the other songs. It was fast and painless but now, have to select a button at the top and then click on each song. Maybe I just really notice these things cos I use all these MS apps whereas many others don't use them.
For me, continuum, the notification center and windowed modern apps with Windows 8.1 would be the OS I'd have been waiting for. Add in updated modern apps with similar features as the preview but still using the old design language and would have been golden.
All in all, Windows 10 is definitely not as touch friendly. I noticed this from day 1 up till today (3 months later) when I finally reverted so it's not really. Eventually, I'll need to make peace with the new way but will avoid it for now.