Speaking of Diamonds Are Forever, a huge reason the film must be considered a flop is the fact that Sean Connery was absolutely phoning it in. Having originally given up the Bond role following You Only Live Twice, it's clear that the Scot's heart wasn't truly in the character anymore. The lack of severity shown by Connery severely impacts the movie's already-scarce tension. If 007 doesn't seem to be taking the plot seriously, why should the audience? It's important that Bond retains a sense of wit and feigned-aloofness, but this must be offset by urgency at the right moments, otherwise the film becomes a farce. Diamonds Are Forever is a prime example of this.
