The "should" in a statement like that is not a command. Or expected to be interpreted as a demand.
The essay makes a case for one way to look at things. Stating it as an absolute makes it easier to describe. It would be cumbersome and unreadable if it was a form treatise. This is extremely common.
As far as agreement, there are many ways to see the world. Few are right, none are complete, but many are useful. Being able to hold many viewpoints, without needing them to be right or wrong, or even consistent, is the beginning of efficiently acquired and scalable wisdom.
The idea that unique experiences can results in unique value obviously has some merit. We have probably all implicitly applied this rule in part, when making decisions or in our perceptions. The essay makes it explicit, clearer.
I will refrain from making any "should" recommendations here.
> The "should" in a statement like that is not a command. Or expected to be interpreted as a demand.
Personally, if the author's intention was what you suggest, I would argue this kind of writing is "lazy" for lack of a better word. Words have specific meanings, and they matter. The most simple (and I would argue proper) understanding of "your life’s goal should be to become the most improbable person you can be" is the plain text reading: the author is offering very specific advice which he follows with an argument for why it is good advice. In other words, he really means your life’s goal should be to become the most improbable person you can be as he stated.
> Being able to hold many viewpoints, without needing them to be right or wrong, or even consistent, is the beginning of efficiently acquired and scalable wisdom.
One can obviously consider multiple viewpoints and choose whether to embrace them or not. But in my opinion, wisdom comes from first-hand experience accumulated over a lifetime. It is not something that is "efficiently acquired", nor is it inherently "scalable."
Knowledge, on the other hand, can be efficiently acquired and scaled. But it is not always easily applied.