From the history of Windows I am familiar with: 95, 98, 2000, NT, XP, Vista, 7, 8 your understanding of Nxt 1.0 - Nxt 2.0 differences is completely off base. Is Windows 10 that much more different from 8 than 8 from 7 or XP?
That's hardly the point but yes, if you get to know the different versions of the system and depending of your usage of it, there are very significant differences between some of those, especially the most recent one. That was for illustrative purposes only though but since you bring it up maybe I should clarify it a bit more: If instead of calling it an asset-token-share, it would have been added to the set of tools already in NXT and called NXT 2.0, we will have exactly the same thing within just one name instead of 2? I hope the question is clearer now and easier to answer...
NXT 2.0/Ardor is completely new and fundamentally different type of blockhain, just using all present NXT 1.0 features on childchains. Using microsoft OS comaprison, I think its is DOS (NXT 1.0) and Windows (NXT 2.0/Ardor). Here is very rough and ugly infographics, explaining how it will look like:
Won't running another layer on top of NXT have issues in the performance of the platform if the usage will go higher and higher? Why not just develop Ardor's new features in NXT? I am sure it can be done.
Ardor is about childchains, it can not be done on top of present NXT, it's completely and fundamentally different. All NXT 1.0 features will be on the first childchain, while other childchain creators could choose which features from NXT 1.0 they need.
Why is there a need for Ardor features in a childchain? Why not make these features in NXT itself? Is there a technical reason for this? My overall question is what made the NXT developers create Ardor when the features can be added in NXT? Is there really a need for Ardor?