Seems to me that MS has again jumped on the bandwagon far too late and is trying to recreate Windows RT to compete with Google's Chrome OS. Sure, Win 10X will allow users to install legacy apps to a special container, but seriously, how long is that going to last? Microsoft has been pushing for years to have a cloud based OS that's designed to market 'Modern Apps' from the store, and that's where I think this is heading, to be more competitive with Google and the Apple Store.
How successful that will be, who knows? It may very well go the way of RT and Windows Phone to die a very lonely death on the pile of other MS failures. Thing is, 10X is supposedly being preinstalled on new laptops, so users may not have a choice as to whether they end up with 10X when purchasing a new machine. I suppose they could always purchase a desktop PC with the standard Win 10 instead, but that could have a major impact on manufacturers and laptop sales.
Anyhow, it won't affect me directly because I am not in the market for another laptop and probably never will be. I have my trusty HP 2-in-1 and that will do me. If and when it dies, then I will revert to my desktop machines, given I don't get out a lot these days and rarely find the need for a portable PC.