What did John Wayne think of this movie??

It's funny that you should mention that. Here's a bit of relevant trivia I found from IMDb:

Around 1970 there was a concerted effort by several major studios to try and get stars Clint Eastwood and John Wayne to appear in a western together. Eastwood was apparently intrigued and showed an interest but Wayne took quite a dislike to the films Eastwood was appearing in, considering them to be anti-American and overly violent. He also took umbrage to the cowboy anti-hero persona Eastwood was known for portraying and thought the films were too revisionist and betrayed the history of the wild west. On these grounds Wayne was very vocal about refusing to make a film with Eastwood, thinking they would never get on and any film would end up a mess. This movie was one of several ideas that Universal studios were contemplating pitching to Wayne if he was willing to consider a project with Eastwood but as Wayne was not interest the script was massively reworked and the character Wayne would have played was written out.