CHARLEY VARRICK: what were they thinking?

If Walter Matthau is remembered at all today, it's as the cantankerously funny star of numerous Billy Wilder directed or Neil Simon scripted comedies of the 60s or 70s. What's less easily recalled is Matthau's attempt in the early 1970s to break out of that mold and recast himself as an action hero.
In retrospect this sounds like a bizarre notion but it clearly made sense to at least some people with the power to greenlight movies because Walter got to play tough in three movies in a row in 1973 and 1974.
CHARLEY VARRICK was the first of the trio with Matthau in the title role as a smalltime bank robber who finds himself in over his head when he inadvertantly steals a large amount of Mob money during a heist.
Despite direction by Don Siegel and a supporting cast including Joe Don Baker and John Vernon this is a pleasant but undistinguished yarn. It feels like a tv movie but with better production values.
What's truly weird isn't the decision to cast Matthau as a tough guy but to make him a ladykiller as well. Matthau has many talents as an actor but he's no oil painting (unless, perhaps, we're talking about a piece by Picasso from his Cubist period).
Yet all it takes is 2 minutes of tough talk, some token slapping around and a suggestive comment about a circular bed for a formerly hard-as-nails secretary to jump into the aforementioned bed with him for a night of wild passion.
For this scenario to be even marginally plausible requires not only that disbelief be suspended but also hanged, drawn and quartered.
I've read that Matthau hated CHARLEY VARRICK, but really, he only has himself to blame for allowing himself to be so monumentally miscast.