I came up with this at about one in the morning. You know how authors say things like "I bolted awake with an idea"? That specific thing happened.
When I speak English, I am forced to contend with the fact that words mean different things to different people, that some collections of words may be figurative, metaphorical, or otherwise not meaning what they actually say in the way I might expect. But the question of what was meant by a given word or phrase is not always welcome. Even the most well-meaning of people will get frustrated with you constantly stopping a conversation to ask what was meant by a particular word. Or in the worst case, someone will immediately dismiss you as not being worth talking to if you don't immediately understand them.
This is a description of speaking language as somebody with autism. Everything is confusing, you are constantly questioning what you understand, and some people are actively hostile to you trying to understand.
In Toki Pona, asking somebody what they meant by a word or phrase is not only widely accepted- it's the norm. The expectation. There is no way to communicate but to ask, and literally everyone is happy to explain what they meant.
Toki Pona's minimal design is not the only point of interest for those with autism. It is also interesting because it solves one of the most fundamental communication problems that those with autism have, and it solves it at the social/pragmatic level where it needed to be solved, by being a language where the question of what you meant must be welcome and answered for the language to function.