I think it is also very much a chicken-and-egg problem. Without software for personal computers, there is no need for personal computers. When there are no people with personal computers, it is not interesting to write software for personal computers.

Then again, why would someone want a personal computer in that time? The things computers are used for now are broadly: 1. Multimedia 2. Communication 3. Administration 4. Computing (for example in science or finance)

The only purpose where you actually need a computer is for computing. This is not something that you typically do at home. It was simply not conventional to use a computer for other purposes at the time. There were no fancy HD screens and the like, and no ubiquitous internet access.