I think before the critics will be satisfied, one would have to make an entirely CGI film that wasn't Sci Fi, or fantastic in its setting or characters.
Exactly. I was thinking about something like an Elvis Presley biopic, but your example will do just fine (except that I don't think that vanilla westerns are commercially viable today).
Vanilla Westerns?!? There is Nothing Vanilla about a Sergio Leone Western! And Clint Eastwood's Unforgiven was an awesome western, as were Silverado and 3:10 to Yuma (and there are even more that have made a fair killing at the box office).
Westerns are not usually thought of as Block-Busters though, but they do draw a big enough crowd to be profitable.
If one were to draw together Lee Van cleef, Clint Eastwood, and Eli Wallach from their Sergio Leone days together with some of the Big names in Action flics today to make a period western that starred all of ...
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.