From what I remember, people were actively promoting Python as the first programming language already in the 90s. Many universities started teaching Python, creating a steady supply of non-CS majors who were familiar with Python but no other language. And because the community was there, people started building the ecosystem.
In contrast, I've never really encountered anyone advocating for Ruby outside web development.
van Rossum was one of the implementers of ABC, which indeed was created to experiment with how to develop a programming language for beginning programmers. (Note: he was not one of the designers of ABC.)
While van Rossum drew from that experience when making Python, the initial driving goal was as a scripting language for system admin tasks in the Amoeba distributed operating system.
In contrast, I've never really encountered anyone advocating for Ruby outside web development.