Do you honestly think that the general public gave two shits about closed architectures?
The vast majority of people, who were using computers, were using them to play games. People completely misremember how little interest the general public had in computers (for serious tasks) at the time.
The only exception to that really was the IBM PC. It didn’t have an open architecture either. For a long time it was the case that if you didn’t buy an IBM branded PC, you couldn’t guarantee that any software would actually work on it.