[theagilecoder]

No the scholars did not start immediately misinterpreting it. For example, rishi katyayana who came after rishi panini in his commentarty correctly understands the rule but somehow later scholars started misinterpreting it and it carried to this day until rishi rajpopat went back to the original source and deciphered it correctly (such a funny coincidence his first name is rishi lol)

I am not sure I understand your question. Ashtadhyayi was written by rishi panini to probably codify the already spoken sanskrit language under the umbrella of his 4000 rules. Probably he was frustrated by seeing different people speaking the language in different ways so I guess he and the 10 other rishis predating him that he credits in his book started this exercise.