Why we use QWERTY (or QWERTZ) keyboard?
You may wonder why letters on your keyboard are in this non logical order. It will be better if from the beginning of computer use they were in for example alphabetical order. Why and who decide to put letters in this order? If it is the most ergonomic way of letter organization? Maybe when we rearrange our keyboards out writing become very fast and bugs free.
Let's start from last question. Is QWERTY the most ergonomic keyboard type? Not really. The way of key organization came from typewriter. In 1873 E.Remington and sons company introduced the QWERTY arrangement to they typewriter. They don't do that to speed up typing. They do that to slow typing down. Main problem in a traditional typewriter was jamming of typewriter fonts. When operator was pressing letters too fast they jam and it take a lot of time to fix it. So Remmingtons speed up whole typing process by slowing typist.
There is a lot of other keyboard layouts but the most popular is Dvorak layout. It was patented by August Dvorak and William Dealey in 1936. The analyze frequency of letters and hand anatomy and base on that they found more human friendly layout. We may argue which layout is better but world record in fastest typing was bet by Barbara Blackburn who wrote 150 word per minute by 50 minutes using Dvorak keyboard.
First computer, especially personal computers like that made by Steve Jobs and Steve Wozniak in garage take as many from existing parts as they can. For them use of typewrite keyboard was natural. It was better to take something that exists and work well. And when people get use to something it is very hard to convince them to something new even if it may be better. Like they say : “habit is our second nature”. So QWERTY layout came to computers from typewriters and stay to this day.
People try to improve usability of keyboard in many ways. The construct ergonomic keyboards, virtual keyboards, on-screen keyboards etc, but I think that the next step in human-computer interaction will be mind controlling or something similar rather than keyboard and mouse evolution.