With MacGruber making a dismal $4.1 million at the box office this weekend, Saturday Night Live's Lorne Michaels is learning a valuable lesson: Fool me once, shame on you. Fool me twice, shame on me. Fool me over and over again, consistently, for two decades, including a Stuart Smalley movie for crying out loud, shame on you again.

MacGruber got almost nothing but positive buzz after its South By Southwest premiere in March. It now has a 52% rating at Rotten Tomatoes, which isn't a great score -- but it the 4th-highest among all SNL-based films. Only The Blues Brothers (84%), Wayne's World (84%), and Wayne's World 2 (59%) got more favorable reviews. Meanwhile, Shrek Forever After has about the same Rotten Tomatoes rating as MacGruber, yet it made $71 million this weekend. What's the difference? Among other things, the Shrek franchise has a lot of built-in goodwill, while the SNL franchise is one of the most hated in all of moviedom.

At this point, it would seem that an SNL movie's actual quality is almost irrelevant. The bad ones have poisoned the well so thoroughly that audiences are almost irreversibly skeptical. They expect SNL movies to be lousy. The brand is almost as tainted as National Lampoon. After SXSW, when I wrote my MacGruber review for Cinematical, the comments people posted showed their incredulity. One commenter insisted -- anonymously, of course, as is the way of cowards -- that my positive review MUST have been bought by NBC/Universal. Mind you, this guy hadn't seen the movie, like I had. But it was unfathomable to him that MacGruber -- or any SNL movie -- could be funny.