It’s more that they sharply diverge from the core ethos of the books.

Dumping the admittedly misogynistic bent of the source material was a great move (including switching the gender of one of the core protagonists). Pretty much every other change made around the foundation-centric plots was straight up poor show running and writing. It goes from high sci-fi to “just another future-y action show”. And many of the plot changes are just.. completely nonsensical.