This is a UI validation problem.

Apple proved in 2007 that you can port tons of applications over to the smartphone. They had to invent their own language for interactions though ("pinch-to-zoom" etc) and it took them two weeks of focus with all their software development staff involved to fix keyboards on capacitive touch.

It may not be possible to reach the same kind of flexibility on a mobile device when it comes to rich text editing, but it's certainly possible to port over a lot of functionality from the desktop.