Rooster Cogburn and 007

Mrs. Schoen was one of my most influential teachers. Actually, she was the junior high school librarian, but I hung out in the library a lot. She encouraged my growing interest in the Civil War, and she suggested I read something other than "Old Yeller" for a tenth time. Heaven only knows what she would have thought of kids re-re-reading the "Harry Potter" books. I say reading is good, period.
One day we were discussing movies, and I asked if John Wayne had won the Best Actor Oscar for "True Grit." She didn't know, she said, but he shouldn't have. I was a bit taken aback. That award, she continued, is for acting, and John Wayne only plays one role – John Wayne.
Mrs. Schoen could be a bit harsh, but I've always thought she had a point. (Wayne did win for "True Grit," by the way.) Still, this is entertainment, and rule No. 1 is "Give the people what they want." More snidely, this can be read as "Find something that works and beat it to death." John Wayne is hardly the first or last actor to figure this out. Sylvester Stallone and Chuck Norris spring to mind. 
TCM aired "Rio Bravo" again last night. It's half a century old and hasn't lost a thing. The remake a decade later, "El Dorado," is watchable but not nearly as good, despite Robert Mitchum as the second banana. TCM also graced us with the first two Bond movies – "Dr. No" and "From Russia With Love" – back to back on Saturday. Again, two movies that are pushing 50, and they're still entirely enjoyable.
So what's going on here? Why does a series last? Bond has survived six different leading men and basically a new villain every time around. Why are we drawn to, say, John Wayne westerns – not specifically a series but close enough? Is it atmosphere? Is it that "Thunderball" is like a cultural time capsule? Is it the mountains of New Mexico and lots of horses? Is it just good versus evil? We learn little new about the main character, we know who the good guys and bad guys are, and we know how things will end. So what pulls us back? ... And who is the John Wayne of our era?
I invite comments. Feel free to be as harsh as Mrs. Schoen if need be.