Shall and Why MSFT needs to keep Win RT?

I know there are some voices calling MSFT to kill it but from my point of view here are some of the reasons why MSFT needs to keep it;

1. Longer battery life.

2. Thinner & lighter hardware designs.

3. Lower cost; now (value = style + quality) before (value = scrappy netbook + cheap quality)

4. Extra level of security (not affected by malwares designed for x86).

5. Windows marketplace is expanding significantly (Unity Game Engine is supported and MSFT is working toward unified ecosystem across all platforms).

6. Speed and performance surely will be boost in 2nd generation Win RT devices by latest ARM Chip NVIDIA Tegra or equivalent chip.

7. Future production of less than 10" tablet form factor (Win legacy apps are hard or impossible to be used in 7-8 inch form tablets because it is a tablet and most of people wouldn’t prefer attaching a mouse to it).

8. Similar to other platforms such as IOS & Android "Consumer Experience".

9. The needs of many people won’t go beyond Browsing, email, social network, gaming, files management system, media consumption, printing, light use of Office apps "FOC / bundled" (soon Office will be available in modern metro). More over MSFT has less worried in near future of those in business environment and high productive user than those who are fine in living with mobile, phablet and tablet (MSFT needs to gain in the market where it’s presence was almost nil).

I am sorry if some of the context is incomprehensible