Yes the taller person has to crouch over more than a shorter person, its just the way it is, to get down below the screen, however if you have short arms it would also force you to lean over the tank more also to reach all the controls.
There are all kinds of parts you can buy from longer or shorter or taller or smaller handle bars to taller shocks or shorter shocks bikes with taller frames to a company called dog bonz that makes a shock package shorter or taller depending on your needs. There are bikes out there for people of almost any size. It depends on what you want and what you can afford and how you want your bike set up.