That's like a big chunk of my point. :) Phone/tablet keyboards really suck for anything other than short human-language text entry. You wanna write a five-page paper? A code snippet to demonstrate a problem? Forget about it.
It's astonishing that these devices have been around for at least seven years and their packed-in keyboards still fail at these tasks.
No reason, apart from economics, why even with current IDE technology we couldn't make one that works well for specific programming languages.