Remind me to never let my iDevices anywhere you then. Fluid damage is the number one killer of all that's electronic
There's a lot of tech that could easily be implemented into these devices, the example of the keyboard projector being one that would be relatively simple. Except for one thing - battery drain. The kind of lighting required by the projector, even over the short distance demonstrated, would sap a phones battery in around 30 mins to an hour.
The biggest complaint that's aimed at the manufacturers of tech goods is battery life. Most people get barely a full 24 hours out of their smartphone as it stands. Something like that keyboard projector would reduce that to the point of constant customer complaints - not good.
Basically battery technology isn't up to what we would like, or even demand from todays mobile phones. Although its made significant progress over the last few years the user demands often outstrip the advances being made.
By the way I can get a solid 4 days use out of my iPhone on a single charge. That's including data tethering, calls, texts, and a bit of gaming, but that's only because I turn on services when I need them, and turn them off when I don't. Most people won't do this, and then have to deal with the phone running out of juice in a single day.