Edit: which mysteriously doesn’t appear to link on my end.

https://en.wikipedia.org/wiki/Demographic_history_of_Palestine_(region)

I know in your example you’re trying to give the right answer or explanation as you see it, but this is also very closely related to Cunningham’s Law:

The best way to get the right answer on the Internet is not to ask a question; it’s to post the wrong answer.

So you’re still providing a service even if it feels bad to have an expert steamroll whatever perception you had. Chances are tons of people had the same vague notion as you and your misguided logic eventually led to the correct path.