"Why can't I 'side load' apps onto my Windows RT-based tablet?"

I question the validity of comparisons to shutting down or closing apps on desktops to iDevices and similar systems. Many of my desktop users (most of the older / lower income ones?) don't have experience with these devices. Heck, my question probably gives away my own lack of exposure to them. But maybe we're in the minority.

I don't think closing apps is as necessary as it used to be, simply because most systems are overpowered for what they're used for in the workplace. On the other hand, I have some users that will never remember to perform a 'Save' until closing an application prompts them to do so.