Really? Wow, that’s too bad. Read some of the books he wrote in the 70s and 80s. Really good stuff and not a hint of what you mentioned. But, people often change mentally when they get older.
He wasn’t a great writer, but it’s definitely a little odd that none (I’ve ever noticed anyway) of his series of books were ever made into a movie. “Inherit the Stars” would make a massive-ass film, and it has built-in sequels. If I had the cash, I’d produce it, and get Terry Gilliam to direct it, and watch it go over budget by $100 million I’m sure. ;’)