We watched Ghostbusters last night, on a whim (thank you, Netfix Instant Play), and Boyfriend couldn't get over how much of a jerk Peter Venkman was. He theorized that Bill Murray played pretty much only jerks up until Groundhog Day, and nicer people after. When I asked why, he guessed it was because of his age. I'm not sure if that means that as Murray got older playing a jerk seemed less attractive, or whether movie makers are less likely to cast older people as jerks. Or maybe it's a crap theory. I don't know, we were drinking last night.
I think Murray inadvertently typecast himself by accepting roles that were naturals for him- and the audience to receive him - the sloppy quirky SNL alumni. He played basically the same character in Stripes, Caddyshack, Ghostbusters, and flopped during a dramatic adaptation of Maugham's
The Razors Edge filmed during the same period, which he co-wrote the screen stuff. Ghostbusters was done in trade, to acquire financing for Razors Edge. After that, he apparently used the personal failure as a reason to disappear for a while, and studied philosophy at the Sorbonne. (note that his IRL moves closely followed the bearded Larry character in Razor's Edge, whom he played, dropping out of life for a while to find himself in Europe).
Re-emerging from that period, he gravitated towards more serious roles, even if they were comedy. Groundhog Day and What About Bob were both about good-hearted men who become unstable in a stable world - both of those movies could have easily become dark without the goofy-happy Murray. I think whats really cool for him is he was finally accepted as a serious actor in Lost In Translation - which should be noted that it carries that Razor theme of a man out of his element - an unhappy movie star in Japan doing work as a shill, still learning about life, and trying to find happiness.
So, I think the thing about playing the grubby sneering roach became less appealing to him, as he matured as an actor and a person.